DINING WITH DIPLOMACY : Sunday lunch with his family was a tradition that the new ambassador from the Philippines, Emmanuel Pelaez, maintained until his assignment.

The Philippines’ new ambassador to the United States, Emmanuel Pelaez, is very much a family man. The Pelaez home in Ayala Alabang, a subdivision on the outskirts of Manila, was a lively place each weekend--doors opened to the breezes, children dashed about the yard or splashed in the pool and a barbecue smoked on the terrace.

“We have always made it a point that Sundays would be family reunion. The children come for lunch and spend the day with us,” Edith Pelaez, said in an interview shortly before leaving the Philippines. The gatherings tended to be large because the Pelaezes have nine children--two now living in California--and 29 grandchildren.

This particular day was one of the last family gatherings before the couple left for Washington, where the ambassador presented his credentials to President Reagan on June 23, the formality that made his post official.

Despite the sudden rush produced by his appointment, the ambassador took time to relax, mix a cup of instant coffee for a visitor and talk about his long political career.

Elected as a congressman from Mindanao in 1949, Pelaez rose to become a senator, then vice president of the Philippines under Diosdado Macapagal, the last president before Ferdinand E. Marcos. During that time, he was assigned to serve as secretary of foreign affairs. When his term as vice president ended, Pelaez returned to the lower house, then again became a senator. In 1972, when Marcos established martial law, the senate was abolished and Pelaez returned to his initial interest, the practice of law. In 1978 he was elected to the Batasang Pambansa, an interim legislature. He retired in 1984 at the conclusion of that term.

Now 70, the ambassador is tall, lean and fit, appearing in excellent health despite a quadruple bypass in 1980. His special interest is rural development, and he speaks with pride of participating in a national rural electrification program that, he said, “brought electricity to more than 2 1/2 million people throughout the country.”

Pelaez would have liked to continue in rural work. “This is where the problem is . . . the agricultural economy is not developed,” he said. Nevertheless, he accepted Corazon Aquino’s invitation to join her campaign and, after her election as president, the appointment to Washington.

“It’s a job to be done. It’s a challenge, “ he said. “There is a need to project the Philippine image in a new light.”

A scholarly man, Pelaez has collected books ranging from the works of the Filipino patriot Jose Rizal to those of Marcos and his wife Imelda. In his Manila home, bookcases line a wood-paneled den that also houses a collection of duck figures in wood, straw, brass and mother of pearl gathered by his wife.

Edith Pelaez is an unassuming woman who seemed slightly hesitant about uprooting her home and moving into the Washington limelight. “We have lived a quiet life,” she observed. Her activities prior to leaving included auditioning a cook to go to Washington.

When lunch was served, one candidate’s try-out chicken dish was included. Also arranged on the buffet were typical Filipino dishes such as pork and chicken adobo; paksiw, a preparation of river fish seasoned with vinegar and garlic; mongo, a savory mung bean stew, and dinuguan, which is a stew made with dried pork, pork blood and vinegar that is eaten with small sweet cakes called puto. Desserts were Leche Flan, French apple pie with a cheese topping, mocha cake roll and juicy, sweet watermelon from Santa Maria, Bulacan.

The ambassador, who is president of the Philippine Bible Society, started lunch by saying grace, tailoring his words to include a benediction for his overseas visitors.

Although the weather was hot, the dining room remained cool and breezy without aid from the ceiling fans. Lined with glass and greenery on one side, it looks through the living room to the lawn and pool on the other. Oriental screens are mounted on the walls, and a large centerpiece of shells decorates the table, which seats 24.

The Pelaezes have maintained a household staff, but that has not kept Edith Pelaez from working in the kitchen. She is so known for her adobo that a restaurateur in Japan sent a chef to Manila to learn how it was prepared. Other specialties include paella and cocido, both usually prepared in quantity for weekend gatherings.

Her father, who came from Pagsanjan in Laguna Province and served for years as provincial treasurer, was “a pretty good cook,” she said. He was also a disciplinarian who believed in practical education.

“My father would always insist that I go to the market with the cook. We always had help, but he insisted that we do some work in the house,” she said.

That teaching remained with her. When her husband was vice president, she still did the weekly marketing, and she often had to prepare meals for unexpected guests.

A versatile dish for buffet entertaining is her cocido. “It’s a complete meal,” she said. Meats and vegetables are cooked in the same broth, which then becomes soup, with beaten egg stirred through it to produce thin strands. The meats--beef, pork, chicken, ham and chorizo-- are grouped separately on one platter. The vegetables--cabbage, green beans, carrots and potatoes--are served on another along with garbanzo and white beans.

Little seasoning is added during the cooking because condiments and sauces served on the side add ample flavor to the dish. “My cocido is not pure Spanish. It’s a mixture of Spanish and Tagalog,” Edith Pelaez said.

Distinctly Tagalog is an eggplant sauce that includes mashed saba banana, a Philippine cooking banana. Tomato sauce topped with fried garlic is another accompaniment. And diners also season the meats and vegetables to taste with olive oil, vinegar, Worcestershire sauce and pepper.

Edith Pelaez rounds out the meal with toasted garlic bread and cold beverages such as cola drinks, calamansi juice and beer that suit the hot climate of Manila. Dessert is often flan, prepared according to her sister’s recipe. The unique method calls for mixing the custard gently with the hands to avoid air bubbles that would spoil the texture. The flan is then steamed in a wok.

The few special ingredients required for the cocido are available in Los Angeles. They include Spanish chorizos de Bilbao, for which pepperoni can be substituted, and country ham, a salty ham available in Chinese markets. Saba type bananas, needed for the eggplant sauce, are also grown in Mexico and can be purchased at Filipino markets. Palm vinegar imported from the Philippines is available at most Asian markets.

EDITH PELAEZ’S COCIDO

1/2 pound small dried white beans

1/2 pound dried garbanzo beans

4 to 5 pounds beef brisket

1-pound country ham

1 1/2 to 2 pounds pork shoulder

1 (2 1/2- to 3-pound) chicken

3 chorizos de Bilbao (Spanish chorizo) or pepperoni

3 pounds potatoes

2 to 3 pounds carrots

2 (2-pound) heads cabbage

2 pounds green beans

1 egg, beaten

Tomato Sauce

Eggplant-Banana Sauce

Vinegar

Olive oil

Worcestershire sauce

Pepper

Garlic Toast

In separate containers, soak white and garbanzo beans overnight in water to cover generously. Next day drain beans. Place in separate pots. Add water to cover generously. Bring to a boil, reduce heat, cover and simmer until beans are tender, about 35 minutes for white beans and 1 hour 15 minutes for garbanzo beans. Drain and keep warm.

Place brisket and ham in large pot. Cover with water and bring to boil. Reduce heat and simmer, covered, until brisket is tender, 2 to 2 1/2 hours. Remove meats from pot and keep warm. Add pork, chicken and chorizos to broth and simmer, covered, until tender, 45 minutes to 1 hour for chicken and chorizos, 1 1/2 hours for pork. Add more water as needed to keep meats covered while cooking. When cooked, remove meats and keep warm.

Peel potatoes and carrots and leave whole. Place in broth. Quarter cabbage. Tie quarters with string and place in broth, hanging ends of string over side of pot to aid in removing cabbage. Arrange green beans in 1 or 2 bunches and tie both ends. Place in broth. Cover and cook vegetables until tender, about 30 minutes.

To serve, slice brisket, ham and pork. Cut up chicken. Slice chorizos. Arrange meats in separate groups on one or more large platters. Place potatoes, carrots, green beans and cabbage in separate groups on one or more large platters. Arrange beans in separate groups on vegetable platter.

Skim fat from broth, strain broth and measure. There should be at least 10 cups. Reserve 1/2 cup for making Eggplant-Banana Sauce. Bring remaining broth to boil. Turn off heat. Add beaten egg and stir to make strands. Serve in cups.

Accompany cocido with soup, Garlic Toast, Tomato Sauce and Eggplant-Banana Sauce. Provide containers of vinegar, olive oil, Worcestershire sauce and pepper to season ingredients as desired. Makes 10 servings.

Tomato Sauce

1 1/2 to 2 heads garlic

1/4 cup oil

1 onion, chopped

3 tomatoes, peeled, seeded and chopped

2 (15-ounce) cans tomato sauce

1/4 teaspoon thyme, crumbled

1/8 teaspoon oregano, crumbled

Salt, pepper

Peel garlic and pound until crushed. Fry garlic in oil in medium saucepan until golden brown. Drain on paper towel and set aside. In same oil, cook onion until tender. Add tomatoes and cook until tender, about 10 minutes. Add tomato sauce and heat. Season with thyme, oregano and salt and pepper to taste. Turn into serving bowl and top with fried garlic. Serve warm. Makes 4 3/4 cups.

Eggplant-Banana Sauce

1 pound Oriental eggplants

1 pound potatoes

6 or 8 saba bananas

1/2 head garlic

1/3 to 1/2 cup meat broth

1 tablespoon palm vinegar

Salt, pepper

Combine unpeeled eggplant, potatoes and bananas in large pot. Cover with water. Bring to boil and cook until tender, about 30 minutes for potatoes, less for eggplant and bananas. Peel and mash together. Stir in meat broth and vinegar. Sauce should be thick enough to mound on spoon, not fluid. Pound garlic until thoroughly crushed. Stir garlic into sauce and season to taste with salt and pepper. Serve at room temperature. Makes 4 1/2 cups.

Garlic Toast

3 cloves garlic

3/4 cup butter, softened

1 loaf French bread

Peel garlic and pound until thoroughly crushed. Mix into butter. Slice bread. Spread garlic-butter on each slice and toast. Makes 10 servings.

LECHE FLAN

1 2/3 cups sugar

10 egg yolks

1 (13-ounce) can evaporated milk

1/2 teaspoon vanilla

Melt 2/3 cup sugar in skillet. When sugar is clear and golden brown, spoon over bottom and sides of deep 8-inch round cake pan. Combine remaining sugar, egg yolks and milk in medium bowl. Mix with hands until smooth. Turn into prepared pan. Place pan on rack in wok over simmering water. Cover wok and steam flan gently until knife comes out clean, about 30 minutes. Do not overcook or flan may curdle and toughen. Remove from wok and cool thoroughly. It is not necessary to refrigerate flan before serving. Invert onto serving platter. Makes 8 to 10 servings.