Prepare Filling:
In a bowl, whisk eggs and milk with salt and pepper. In a skillet, melt butter over medium heat. Add onions and bell peppers, sauté until soft (3–4 minutes). Add sausage, then pour in egg mixture and scramble until cooked through. Stir in shredded cheese and remove from heat.

Make Gravy:
In a separate saucepan, melt butter over medium heat. Stir in flour and cook for 1–2 minutes to form a roux. Gradually whisk in milk, stirring constantly until gravy thickens (about 5 minutes). Season with salt, pepper, and garlic powder if using.

Assemble Burritos:
Warm tortillas. Divide sausage-egg mixture among tortillas and roll into burritos.

Serve:
Plate burritos and generously pour gravy over the top. Serve warm.