Olive oil cooking spray
1 teaspoon olive oil
2 packed cups (3 oz/90 g) fresh baby spinach
3 large eggs, lightly beaten
1 tablespoon whole milk
¼ teaspoon minced fresh oregano
Salt and freshly ground pepper
2 tablespoons crumbled fresh goat cheese
Preheat oven to 350°F (180°C). Spray a 24-cup mini muffin pan with cooking spray.
In a frying pan over medium heat, warm the oil. Add the spinach and sauté until it releases its liquid, about 2 minutes. Drain, squeezing to remove the liquid, then chop finely.
In a bowl, whisk together the eggs, milk, oregano, a pinch each of salt and pepper, and the cooked spinach. Divide the mixture evenly among about 12 of the prepared cups; they should be almost full. Divide the cheese evenly among the filled cups, scattering it on top.
Bake the mini frittatas until the centers are set and the edges are browned and pulling away from the pan sides, about 15 minutes. If you like, turn on the broiler during the last minute of cooking to brown the tops. Transfer to a wire rack and let cool in the pan for 5 minutes. Run a small knife around the inside edge of each muffin cup to release the mini frittatas, then turn out onto the rack. Let cool.
Store It: Refrigerate in an airtight container for up to 3 days, or seal in a zippered plastic bag and freeze for up to 3 months.
Pack It: Thaw 2 or 3 frittata bites, if necessary, then pack in a small airtight container. If you are on the go for more than 1 hour, place in a small bag with a travel ice pack.