1 medium tomato, roughly chopped
1 small white onion, thinly sliced
1 garlic clove, chopped
4 ancho chiles, stems and seeds removed
7 corn tortillas
4 tablespoons safflower or canola oil (plus more for frying)
5 cups chicken broth
1 stem of epazote (optional)
1/8 teaspoon dried oregano
grated queso fresco (optional)
3 limes, sliced
Pour a few cups of boiling water into a bowl. Add one of the ancho chiles. Weight the chile down with a small plate or cup.
Let it hang out for 10 minutes or so. When done, remove the chile and transfer the flesh to a blender along with the tomato, onion, garlic, 1 corn tortilla torn into pieces, and 1/2 cup of water.
Blend until it is a smooth puree.
Add 1 tablespoon of the oil to a large pot over high heat.
When very hot, dump in the pureed mixture. Stir often for 8 minutes. It should have reduced down to a paste.
Pour in the chicken broth and add the epazote (if using). Bring mixture to a simmer and cook over medium heat for 10 minutes.
Place strips of fried tortilla and chile in some bowls, and ladle on the soup. Sprinkle some cheese if you have it on top of then soup and drizzle in some fresh lime juice.