Pre-heat the oven to 190C/375F. Lightly spray or brush a 12-hole muffin tin with oil.
Whisk together the eggs and milk in a large bowl, then stir through all the veggies, herbs and cheese.
Grind in a decent amount of pepper and stir again, then spoon the mixture into the muffin holes (not quite right to the top or the egg will spill over!).
Bake for 10 to 12 minutes, or until the egg mixture in the 'muffins' is set but still slightly wobbly in the middle.
Notes
Adapted from a recipe by Jasmine and Melissa HemsleyThe veggies in this recipe are just a guideline. You can use whatever veg you happen to have in your fridge – grated courgette works particularly well (just squeeze out as much of the water as you can once grated).If you decide to use tomatoes, I’d suggest just laying one slice on top of each ‘muffin’. Just don’t stir them through the mixture as they’re a bit too watery. I found it best to half fill each muffin hole with a variety of the veggies and cheese first, then to drizzle in more of the egg until each hole is about 4/5 full. You want about 50% veggies and 50% egg in each muffin hole.A note about freezing - you might find that the frittatas retain a bit of water when you defrost them and reheat. I didn't mind this too much - they are definitely best eaten fresh, but I still enjoy them after they've been frozen!