Prepare the Filling:

1. Preheat the oven to 350°F (177°C) and spray a 9×13 inch baking dish with nonstick spray.
2. In a large frying pan, brown the breakfast sausage over medium-high heat. Drain any excess grease.
3. Transfer the cooked sausage to a medium bowl and stir in the salsa, ¾ cup cheddar cheese, and ¼ cup Monterey Jack/pepper jack cheese.
4. Add the potatoes O’Brien to the frying pan and stir until heated through.
5. Transfer the potatoes to the bowl with the sausage and stir until well combined.

Assemble the Enchiladas:

1. Spoon ⅛ of the sausage and potato mixture into the center of each tortilla.
2. Roll up the tortillas and place them seam-side down in the prepared baking dish.

Make the Egg Mixture:

1. In a separate large bowl, whisk together the eggs, half-and-half, flour, and salt until well combined.

Bake the Enchiladas:

1. Pour the egg mixture over the tortillas in the baking dish.
2. Sprinkle the remaining ¾ cup cheddar cheese and ¼ cup Monterey Jack/pepper jack cheese over the top.
3. Cover the baking dish with foil and bake for 35 minutes.
4. Remove the foil and bake for an additional 10 minutes, or until the egg mixture is set and the cheese is melted and bubbly.

Serve:

1. Top with your desired toppings, such as chopped cilantro, diced tomatoes, sliced green onions, or crumbled bacon.
2. Serve immediately and enjoy!