Black Bean, Grilled Flank Steak and Guacamole Tostada Stack Recipe from Mexico

Ingredients

• 8 six-inch corn tortillas
• 4 six-inch blue corn tortillas
• vegetable oil , as needed
• 12 oz (340 g) flank steak
• 1 cup shredded monterey jack cheese
• 1 cup cooked black beans , drained
• 0.5 cup sour cream
• 1 cup guacamole (recipe follows)
• 0.25 cup diced tomatillo
• 2 tbsp chopped jalapeño pepper
• 0.25 cup chopped onion
• 0.25 cup chopped tomato
• 1 california avocado , seeded, peeled and sliced