Add the butter to a skillet over medium high heat.
Stir in the ground sausage and bell peppers, and saute until the meat is completely browned.
Mix in the minced garlic, spinach and salt and pepper to taste, and saute until the spinach has wilted. Set aside.
In a small skillet, spread ½ of the olive oil.
Sprinkle in ½ of the cheese, and allow it to brown and crisp up for a minute or two.
Whisk together the eggs in a bowl.
Pour half of the egg mixture into the skillet with the cheese, and cook until it is beginning to set.
Place half of the sausage filling on one half of the egg in the skillet, and gently flip the other half of the egg up and over it to form an omelette.
Flip the omelette to finish browning the other side, and then remove to serve.
Repeat the above steps to make the second omelette.