In a mixing bowl, combine the ground turkey with the salt, black pepper, sage, thyme, marjoram and crushed red pepper. Stir (or mush with your hands or a fork) until the turkey is well combined with the seasonings. Mist a medium nonstick skillet with cooking spray and bring to medium heat. Add the seasoned turkey and cook, breaking up with a wooden spoon or spatula, until the turkey is cooked through and broken into small pieces. Remove the turkey sausage to a side plate and wipe out the skillet with a paper towel.
In another mixing bowl, combine the egg, egg whites and water and sprinkle with a bit of salt and pepper. Whisk together until thoroughly blended and beaten.
For each omelet, mist the medium skillet with cooking spray and bring over medium-high heat. Add the egg mixture to the pan. Use a spatula to push the eggs from all around the edges into the center so that the set eggs are pushed into the middle and the egg liquid seeps back to the edges of the pan. When the edges are set and the center is getting there, sprinkle an ounce of the shredded cheddar in a line down the center of the omelet, then follow with a quarter of the turkey sausage (for me this was 1.8 ounces cooked) so that there is a straight line of filling down the middle.
Use a spatula to fold one side of the omelet over the center filling, then tilt the pan (folded side first) toward your plate and use the spatula to slide the omelet onto your plate and fold the other side of the omelet over the filling. Serve. Repeat to make additional omelets (or you can store the turkey sausage from step one in the refrigerator and use it to make omelets for the next few days.