Combine the cornmeal, warm water, cumin, cheese, butter and salt, mixing thoroughly. Let mixture stand for five minutes.

Knead with your hands for about 3 minutes moistening your hands with water as you work. Preheat the oven to 375 degrees F.

Form small balls with the dough. Spray your muffin tin with non-stick spray. Place one ball in each muffin cup and press with your fingers to make small shells.

Meanwhile mix the avocado, lime juice, salt and pepper in a small bowl. Set aside.

Bake for about 20 minutes. Place them on a serving plate, then fill each bite with shredded beef and garnish with avocado pieces and cilantro leaves. Serve WARM!