Pepián de Pollo (Chicken Stew)

3 medium yellow onions
1 (5-1/2 to 6-lb.) whole chicken, skin and all visible fat removed
3 Tbsp. Knorr® Chicken flavor Bouillon
11 cups water
6 large cloves garlic, unpeeled
1 lb. plum tomatoes
2 dried guajillo chile peppers, toasted and stemmed
2 dried poblano chilies or mulato chilis, toasted and stemmed
3/4 cup (105 g) pumpkin seeds, toasted
3/4 cup (105 g) sesame seeds, toasted
15 whole black peppercorns, toasted
8 whole cloves, toasted
1 medium cinnamon stick, toasted
1 small bunch fresh cilantro
5 tsp. dried Mexican oregano leaves, toasted
6 large carrots, about 1-1/2 lb., peeled, sliced into 1/4-in. thick slices
4 medium potatoes, about 1-1/4 lb., unpeeled, cut into 1/2-in. thick quarter moons
2 chayotes, peeled, pitted and cut into 3/4-in. cubes

1 Peel onions. Cut 2 onions into quarters and coarsely chop remaining onion; set aside.
2 Bring 1 of the quartered onions, chicken, Knorr® Chicken flavor Bouillon and water to a boil in large stockpot over high heat. Reduce heat to medium-low and simmer briskly, covered, until chicken is done and wings and legs pull easily from body, about 45 minutes.
3 Meanwhile, arrange remaining quartered onion, garlic and tomatoes on foil-lined baking sheet or broiler pan. Broil, turning occasionally until lightly charred. Remove vegetables from baking sheet to large bowl as they char, about 12 minutes. Peel garlic cloves.
4 Toast cilantro, turning occasionally, until fragrant and slightly browned, about 5 minutes.
5 Combine roasted vegetables, chilies, seeds, spices and herbs in large bowl, set aside.
6 When chicken is cooked, remove from stockpot and allow to cool. Remove 3 cups cooking liquid cool slightly. Add carrots and remaining chopped onion to stockpot and return to a simmer.
7 When chicken is cool enough to handle, remove meat from bones and coarsely chop or shred; set aside.
8 Combine roasted vegetable mixture in blender. Process in batches, adding reserved 3 cups cooking liquid as needed to make a smooth paste. Be very careful blending if the cooking liquid is hot. Stir into stockpot and return to a simmer.
9 Stir in potatoes and chayote and cook until vegetables are tender, about 8 minutes. Stir in chicken and heat through. Serve with brown rice or green salad.