Preheat the oven to 350. Grease the cups of a 24-cup mini-muffin pan.
In a large skillet, cook the bacon and the onion until the bacon is crisp and the onion is clear. Season with the herbes de provence and salt and pepper to taste. Divide the mixture among the prepared muffin cups.
Divide the cheese and spinach among the prepared cups.
In a large mixing bowl, beat the eggs. Add the half and half. Pour this mixture into the cups, dividing evenly.
Bake for 10 to 12 minutes until the frittata bites are golden and puffy and set in the center. Serve immediately.
Notes
Leftovers can be stored in the fridge for up to 4 days.