Preheat the oven to 400°F.
Pound the turkey cutlets between plastic wrap to 1/4-inch thickness.
In a medium bowl, combine the red pepper, carrot, zucchini, and yellow squash and mix well.
Place a quarter of the veggie mixture at the end of each turkey cutlet and roll up; secure with a toothpick.
In a small bowl, combine whey powder, cumin, garlic powder, onion powder, and dried mustard.
Dip rolled-up turkey cutlet in egg and then roll in the whey powder mixture.
Place the turkey cutlets in a nonstick baking pan and place in the oven for 15 minutes or until the meat juices run clear.
Drizzle lemon juice over the cutlets and serve.