1. In a bowl, use a fork to blend cream cheese, garlic, onions, cheddar cheese, and lime juice.
2. Wearing rubber gloves, cut chilies in half lengthwise. With a knife, cut seed lump from beneath the stem inside each chili, leaving stem end in place (to form a cup). Pull out and discard veins. Fill chili halves equally with cheese mixture, spreading surface smooth.
3. In a small bowl, whisk egg whites until slightly frothy. Put cornflake crumbs in another small bowl. Dip filled chili halves, 1 at a time, in egg whites, then roll in crumbs. Set chilies slightly apart on a 12- by 15-inch baking sheet, filling the sheet.
4. Bake in a 350° oven until crumbs are slightly darker brown and crisp, about 20 minutes. Serve hot or warm.
Nutritional analysis per piece.