Salpicon Tostadas

Ingredients

• 3 tablespoons cooking oil
• 3 pounds skirt or flank steak, chopped in large 3-inch pieces
• 6 cups beef stock
• 3 tablespoons orange juice
• 2 tablespoons lime juice
• 2 tablespoons olive oil
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 3 Roma tomatoes, seeds removed and chopped
• 3/4 cup red onion, thinly sliced
• 1 cup chopped cilantro
• 8 mint sprigs, finely chopped
• 4 cups shredded iceberg lettuce
• 2 serrano chiles, sliced
• 1 1/2 cups cubed Real California Oaxaca cheese
• 12 Corn tostadas for serving
• Avocado slices for serving
• Crumbled Real California Cotija cheese for serving