For the chicken sausage: If raw, cook in a 400°F oven to an internal temperature of 160°F using a thermometer. If already cooked: Preheat a non-stick pan over medium heat and brown the chicken sausage slices on each side.
In a non-stick pan, heat olive oil over medium heat. Add in the tomatoes and egg.
Move the eggs around the pan. Once they start to become firm and fluffy but still a little moist, remove from the heat. Season with salt and pepper.
Portion and top with feta; serve with toast, chicken sausage, and apples.