Wash the aji yellow chili peppers thoroughly and cut off the ends.
Open each chili pepper and remove the seeds and inner veins. If you prefer a spicier paste, keep some of the seeds.
Place the cleaned chili peppers in a pot, cover with water, and boil for 10 to 15 minutes until tender.
Drain and rinse with cold water. Cut the peppers into smaller pieces for frying later.
Chop the walnuts, onion, and garlic and set aside.
Heat 3 tablespoons of vegetable oil in a pot over medium low heat. Add the onion and garlic.
When the onion becomes translucent, add the yellow chili. Reduce to low heat and stir for about 15 minutes until the onions become golden brown in color. Set aside.
Prepare the yellow chili sauce in a blender. Combine the yellow chili, onion, garlic, chopped walnuts (keeping some aside for garnish), and torn pieces of white bread. Add approximately 2 cups of the chicken cooking broth. Blend until all ingredients are well combined.