01 - Heat oven to 350°F and grease a standard muffin tin or use oven-safe silicone liners. Wash, dry and finely chop the vegetables.
02 - Divide vegetables among enough cups to leave room for egg. Whisk egg whites with salt and pepper, then pour over vegetables, stopping around three-quarters full. Add optional cheese.
03 - Bake, starting checks around twenty minutes, until centers are set and reach 160°F. Continue as needed rather than judging only the golden edges.
04 - Rest five minutes, loosen gently and lift out. Refrigerate promptly in shallow containers; do not leave on the counter until completely cold.
# Extra Suggestions:
01 - Vegetable volume and tin size vary. Use additional wells rather than filling one to the rim.
02 - Excess water collects beneath the egg and makes the muffins difficult to lift cleanly.