Kakuni ramen at Ramen Yamadaya is tonkotsu ramen with the addition of a slab of steamed pork belly. (Liz O. Baylen / Los Angeles Times)
Sam Estrada and Jenny Chen dig into classic tonkotsu ramen at the restaurant near the 405 Freeway in Torrance. (Liz O. Baylen / Los Angeles Times)
The Yamadaya ramen includes extra toppings, including a seasoned egg, fermented bamboo shoots and squares of dried seaweed. (Liz O. Baylen / Los Angeles Times)
Ramen Yamadaya offers some of the popular Tokyo variants of tonkotsu. (Liz O. Baylen / Los Angeles Times)
