Guatemalan Tostadas

Name: Guatemalan Tostadas
Prep time: 5 min
Cook time: 30 min
Total time: 35 min
Cuisine: American, Latin American
Ingredients: 2 Lb of black beans; 2 Onions; 1 tbsp of Adobo seasoning; Salt to taste; Vegetable oil; 6 Tomatoes; 1 Small onion; 1 Garlic clove; 1 Sweet pepper; 1 tbsp of Vegetable oil; 3-5 Hass avocados; ½ Onion, finely diced; 2 Limes; 1 tsp of Oregano; Salt and pepper to taste; 12 Cold, thin tortillas (or 12 toasted tortillas); Oil for frying the tortillas; Bunch of cilantro, chopped; 1 Onion, sliced in rings; 1 Queso Duro (crumbling cheese)