4 flank steaks (6 to 8 ounces per person)FOR THE SAUCE
1 (8-ounce) package guajillo chiles
8 cloves garlic, still in their skins
Vegetable or grapeseed oil
1 quart chicken stock
Kosher salt
1 white onion, sliced into half-moons
½ cinnamon stick
1 teaspoon whole black peppercorns
1 teaspoon dried Mexican oregano
A pinch of sugar (optional)The night before or at least a few hours before you plan to serve
this, marinate the steaks. To make the marinade, start by soaking
the chilies in hot tap water for 30 minutes to an hour until they’re
rehydrated and mostly soft. Meanwhile, place the whole garlic
cloves in their skins in a dry cast-iron skillet and turn the heat to
medium. Slowly toast the garlic cloves, lowering the heat slightly
and shaking the pan every so often, until they’re slightly charred
on the outside and begin to turn golden on the inside (it’s okay if
there are a few charry spots on the inside too). When a knife goes
through the garlic easily, remove from the skillet, discard the skins,
and add the garlic to a blender. Cut the stems off the softened
chilies, slice them in half vertically, remove the seeds and