Heat olive oil in a large skillet over medium-high heat. Add the sausage and cook, breaking it up with a spoon, until browned and cooked through, about 5-7 minutes. Transfer to a plate and set aside.
In the same skillet, add the sliced onion and bell pepper. Cook, stirring occasionally, until softened and lightly charred, about 4-5 minutes. Season with salt and pepper.
Warm the tortillas in a dry skillet or microwave for about 20 seconds each to make them pliable.
Lay a tortilla flat and spread about 1 tablespoon of mayonnaise or ranch dressing (if using) down the center. Divide the cooked sausage, sautéed vegetables, and shredded cheese evenly among the tortillas.
Fold in the sides of the tortilla, then roll tightly from the bottom to enclose the filling. Repeat with remaining tortillas.
Place the wraps seam-side down in a clean skillet over medium heat. Cook for 2-3 minutes per side, until golden brown and the cheese is melted. Alternatively, you can serve them cold or at room temperature.
Tips
For extra flavor, use spicy or Italian sausage.
Add a handful of fresh spinach or arugula for a peppery bite.
To make ahead, assemble wraps without cooking, wrap in foil, and refrigerate. Reheat in a skillet or oven at 350°F for 10 minutes.
Serve with salsa, sour cream, or hot sauce on the side.