1. Pre-heat oven to 350F.
2. Cut sweet potato into small cubes and boil, steam, or microwave until tender. Drain well and set aside.
3. Grease or line muffin tins.
3. Pan-steam the leeks and garlic in water over medium heat, until soft, about 10 minutes. Cool.
4. Stir into leeks the feta and sweet potato. Divide among the muffin tins.
5. Whisk the egg beaters and non-fat milk together and season with pepper or Mrs. Dash. Pour the egg mixture into each hole until three-quarters filled, then press the vegetables down gently.
6. Bake for 25-30 minutes, or until golden and set. Leave in tins for 5 minutes, then ease out with a knife.