3 whole chipotles in adobo plus 2 tablespoons adobo sauce
3 bay leaves
Mexican crema, for garnish
Season the chicken generously with salt, pepper, and the Dijon mustard. Let sit for 10 minutes.
Cook the tomatoes in a pot over medium-high heat with just enough water to cover them, stirring occasionally, for about 10 minutes.
Preheat your oven’s broiler to its highest setting. Place the chopped onion on a baking sheet and broil for 10 minutes on your oven’s highest rack, until lightly charred. Add the garlic to the pan and broil for another 5 minutes. Set aside.
Heat the oil and butter in a very large, deep skillet or saucepan over medium-high heat. When the fat starts to smoke, drop the seasoned chicken into the pan and brown it on each side for about 5 minutes.
Meanwhile, in a blender, mix the charred garlic and onion, the cooked tomatoes, and the chipotle chiles and adobe sauce until finely pureed. Pass through a double-fine-mesh strainer for a velvety texture. Add the chipotle mixture to the skillet along with the bay leaves and mix well with the chicken. Bring to a simmer, cover, and let cook for 10 minutes.
Once the sauce starts to change color and the texture resembles heavy cream, it is ready. Drizzle with Mexican crema.