Process first 4 ingredients in a blender until blended. Stir together chives and next 2 ingredients in a small bowl.
Place 8 lightly greased 4-inch (6-oz.) ramekins on 2 baking sheets; layer tomatoes, 1 cup cheese, and chive mixture in ramekins.
Pour egg mixture over top, and sprinkle with remaining 1/2 cup cheese.
Bake at 450 for 7 minutes, placing 1 baking sheet on middle oven rack and other on lower oven rack. Switch baking sheets, and bake 7 to 8 more minutes or until set.
Remove top baking sheet from oven; transfer bottom sheet to middle rack, and bake 1 to 2 more minutes or until lightly browned.
Mixture will rise about 1 inch above rim of baking dish. Hands-on time: 10 min.; Total time: 30 min.