mini ham and cheese frittatas

One of my favorite breakfast meals to make for the family.enjoy they are so good :)
Mini ham and cheese frittatas

Ingredients
Cooking spray
1/2 cup finely chopped onion
2/3 cup chopped reduced-fat ham (about 2 ounces)
1/3 cup (about 1 1/2 ounces) shredded reduced-fat extra-sharp cheddar cheese
2 tablespoons chopped fresh chives
1/8 teaspoon dried thyme
1/8 teaspoon black pepper
4 large egg whites
1 large egg
Preparation
Preheat oven to 350°.
Heat a large nonstick skillet coated with cooking spray over medium-high heat. Add onion; sauté 2 minutes or until crisp-tender. Add ham; sauté 3 minutes. Remove from heat; cool 5 minutes. Combine remaining ingredients in a large bowl; stir with a whisk. Add ham mixture, stirring with a whisk. Spoon mixture into 24 miniature muffin cups coated with cooking spray. Bake at 350° for 20 minutes or until set