Heat 1 1/2 tablespoons butter in a large nonstick skillet over medium heat.
Add the hash browns and cook, stirring occasionally, until golden brown, about 15 minutes.
Meanwhile, heat the remaining 1/2 tablespoon butter in a small saucepan over medium-high heat.
Add the onion and cumin and cook, stirring occasionally, until the onion is softened, about 5 minutes.
Add the beans and salsa, reduce the heat to low and cook until heated through, about 2 minutes.
Lightly beat the eggs in a bowl with 1/2 teaspoon salt, and pepper to taste.
Pour into the skillet with the hash browns and cook, stirring, until the eggs are almost set, about 2 minutes. Stir in half of the cheese and cook until the eggs are just set, about 1 more minute. Divide among the tortillas and top with the bean salsa, avocado, cilantro and remaining cheese.