Preheat the oven to 300 degrees F, and arrange an oven rack in the center position. Place silicone liners into a muffin pan (or generously grease paper liners) and set aside.
Add the egg whites, cottage cheese, and Monterey jack cheese into a blender. Cover and blend for 20-30 seconds.
Add the roasted red pepper and spinach to the blender. Cover and pulse 4-5 times.
Pour the egg white mixture into the prepared muffin liners. Bake for about 26 minutes or until the egg whites are set.
Remove from the oven and cool in the pan on a wire rack for about 5 minutes. Then remove the egg white bites from the liners and cool them to room temperature or enjoy warm.
Notes
You can use paper liners instead of silicone liners. Just be sure to grease paper liners generously with non-stick cooking spray.
For the egg whites, you'll need about 11 eggs to equal 1 ⅓ cups. Or you can use liquid egg whites in a carton (like Egg Beaters or Bob Evans brand), which is the more budget-friendly option, especially if you're making a big batch for a crowd.