- Preheat the oven to 350˚F (180˚C). 
- Lightly grease a muffin tin. ( Coconut Oil) 
- Then divide equally the spinach across 6 cups. 
- Dice the tomato, then fill the cups with the tomato and egg whites. 
- Season with salt and pepper. 
- Bake for 15 minutes, or until the whites have set.