1. Whisk lime juice and honey in a medium bowl. Stir in mangoes, cucumbers, and cilantro. In a separate bowl, toss lettuce with vinegar.
2. Heat oven to 450 degree F. Brush tortillas with 2 teaspoons oil, place on a cookie sheet, and bake until crisp, 5 minutes.
3. Meanwhile, heat remaining oil in a nonstick skillet over medium-high heat and cook onion until translucent, 5 minutes. Add beef and garlic and cook until meat is no longer pink. Transfer to a bowl with a slotted spoon. Stir in salt, cayenne pepper, and cumin.
4. To serve, layer beef over two tortillas. Top with lettuce, avocado, and salad. Makes 4 servings.