For the sauce:
2 pounds tomatoes, cored and cut in half, lengthwise or 2 15-ounce cans of diced tomatoes, preferably fire roasted
1 jalapeño, seeds and stem removed, cut in half lengthwise
3 garlic cloves
1/3 medium yellow onion
1/2 teaspoon ground cumin
1/4 teaspoon ground allspice
1 cup chicken broth
1 teaspoon vegetable oil or lard
2 tablespoons chopped cilantro
Salt to taste

For the entomatadas:
1 tablespoon vegetable oil or lard
12 corn tortillas
4 cups grated Monterrey Jack or Muenster cheese (16 ounces)
Avocado slices for serving