Remove stems and seeds from the dried chiles. Toast them briefly in a dry pan over medium heat—just until fragrant, 10–15 seconds per side. Then soak them in hot water for about 20 minutes to soften.

In the same pan, lightly toast the nuts or seeds, then the tortilla or bread pieces until golden. Set aside.

Add a little oil to the pan, and cook the onion, garlic, and tomatoes until softened and slightly caramelized.

Drain the chiles, and in a blender combine them with the sautéed vegetables, toasted nuts/tortilla, cinnamon, cloves, cumin, chocolate, and about 1 ½ cups of broth. Blend until very smooth, adding more broth if needed.

Heat 1 tablespoon of oil in a pot. Pour in the blended mixture carefully (it may splatter) and cook over medium heat for about 15–20 minutes, stirring often, until it thickens and the flavors meld. Add sugar and salt to taste, adjusting the consistency with more broth as needed.

Spoon the mole over warm cooked chicken, sprinkle with sesame seeds, and serve alongside rice or tortillas.