Foil line a cookie sheet and place a rack on top of it, for the tomatoes, garlic bulb, poblanos, and tomatillos, charring under the broiler until the skin has blackened. Start with about 7 minutes on high, flip the items over, then another 7 minutes. My poblanos took about 4 minutes extra.
Set aside to cool. Once cool, slip the skins off the tomatoes and the poblanos.
Place the tomatoes, poblanos, roasted garlic, and tomatillos in a small food processor and break down.
Add some oil to a dutch oven and generously dust the beef pieces with the rub and brown. Make sure to do it in batches and don't crowd the pan! Remove from pot and set aside.
Add a couple tablespoons of oil and add half the mushrooms, leeks, and pearl onions. Season with salt and pepper. Saute until the leeks soften and the mushrooms shrink a bit.
Move the mix to the side of the pan, add a bit of oil to the bare side, and brown the cumin seeds.
Mix everything together.
Add the rest of the mushrooms, stirring to mix. Saute for about another 5 minutes.
Add the beef, spices, tomato chili mix, and beef stock and stir to mix.
Nestle the whole dried ancho chili and bay leaves in.
Cover and cook for 1 1/2 hours at 350°F.
