Heat a nonstick skillet over medium heat. Add sausage; crumble and cook sausage for 12-15 minutes, or until cooked through and browned. Remove from skillet and set aside.
Add oil to the same skillet and let it heat slightly over medium heat. Evenly distribute potatoes in skillet; cook potatoes, stirring occasionally, for 10 - 15 minutes, or until golden brown and potatoes. Season with garlic, salt and pepper. Return sausage to skillet and stir until combine. Keep it warm.
Top the tortillas with equal amounts of the sausage-potato mixture. Add salsa and sprinkle with the cheese. Add a fried egg on top, sliced avocado, and salsa, if using.
Garnish with cilantro and lime wedges. Serve immediately.