Kitchen gadget: Heat diffuser

The above contraption may look a little funny, but it can be essential in the kitchen. Meet the heat diffuser.

When you have a recipe that requires stove-top cooking over an extremely low and gentle flame, or are using a delicate cooking vessel such as a clay pot, a diffuser is perfect for softening and evenly spreading the heat. And it’s great for eliminating hot spots.

A heat diffuser (like the much-loved one pictured above from the Test Kitchen) is easy to use: Simply set the diffuser over the burner and place your pot or pan on top, then start cooking.

They’re relatively cheap; a diffuser should set you back no more than $10 to $15 at most cooking supply stores (they’re also easy to find online).

If you have any kitchen tips or questions you’d like me to explore, leave a comment below or shoot me an email at noelle.carter@latimes.com.

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Moroccan lamb tagine with melting tomatoes and onions

Total time: 3 hours and 45 minutes

Servings: 4 to 6

Note: Adapted from “Mediterranean Clay Pot Cooking” by Paula Wolfert. She recommends a glazed earthenware or Flameware tagine, or a 10- or 11-inch Spanish cazuela with a cover. She also recommends using a heat diffuser for slow, steady cooking (especially if using an electric or ceramic stove top).

The flour tortillas are a substitution for Moroccan flatbread. Cubeb berries can be ordered online.

2 1/2 pounds thick bone-in lamb shoulder arm chops

3 tablespoons golden raisins

1/2 cup hot water, plus warm water for rehydrating the raisins

3 large red onions, 1 grated, and 2 thinly sliced, divided

2 teaspoons Moroccan spice mixture (see below)

1/4 teaspoon ground cubeb berries or cayenne

1/8 teaspoon saffron threads

1 3-inch Ceylon cinnamon stick, lightly crushed (often sold as Mexican cinnamon)

Salt

1 tablespoon unsalted butter

3 tablespoons mild olive oil, divided

6 plum tomatoes, preferably Roma, peeled, quartered lengthwise and seeded

Freshly ground black pepper

2 tablespoons turbinado sugar mixed with 1 teaspoon ground cinnamon

6 flour tortillas

1 tablespoon chopped fresh flat-leaf parsley

1. Trim any excess fat from the lamb. Cut the chops into 1 1/2 -inch chunks with the bones.

2. Soak the raisins in warm water for 15 minutes to rehydrate them.

3. Meanwhile, place the lamb, grated onion, Moroccan spice mixture, cubeb berries or cayenne, saffron, cinnamon stick, 1 teaspoon salt, butter and half the oil in the tagine. Place on a heat diffuser if possible, uncovered, over low heat until the aroma of the spices is released, about 10 minutes. Do not brown the meat. Add the half-cup hot water and gently increase the heat to slowly bring it to a boil.

4. Drain the raisins. Cover the meat mixture with the onion slices and raisins and spread the tomatoes, cut side down, on top. Cover the tagine, reduce the heat to low and cook until the lamb is tender, about 2 hours.

5. When the lamb is almost ready, set an oven rack on the middle shelf of the oven. Heat the oven to 350 degrees.

6. Remove the top of the tagine and tilt the pot to pour all the liquid into a medium conventional skillet. Skim the fat off the top of the liquid; then boil it down to three-fourths cup. Season with salt and pepper to taste. Spread the reduced juices over the tomatoes in the tagine. Remove and discard the cinnamon stick. Scatter the sugar and ground cinnamon on top. Place in the oven and bake, uncovered, for 45 minutes. Switch the oven heat to broil, dribble over the remaining oil, and cook until crusty and lightly charred, about 5 minutes. Serve at once or reheat gently over medium heat.

7. Just before serving, warm the tortillas, tear them into large pieces, and spread about one-third over a large serving platter. Spoon about half the contents of the tagine on top. Repeat with another third of the tortillas and the remaining contents of the tagine. Top with the last of the tortillas and a sprinkling of parsley and serve at once.

Moroccan spice mixture (La Kama)

1 tablespoon ground ginger

1 tablespoon ground turmeric

1 tablespoon finely ground black pepper

2 teaspoons ground Ceylon or Mexican cinnamon

2 teaspoons ground cubeb berries (optional)

1 teaspoon freshly grated nutmeg

Combine the ginger, turmeric, black pepper, cinnamon, cubeb berries and nutmeg and shake well to mix thoroughly. Store, tightly covered for up to 6 months.

Each of 6 servings: 599 calories; 34 grams protein; 41 grams carbohydrates; 4 grams fiber; 33 grams fat; 12 grams saturated fat; 114 mg. cholesterol; 13 grams sugar; 778 mg. sodium.