Preheat oven to 425°
In a medium mixing bowl, add the eggs and whisk until combined. Add the milk, ¼ cup of cheese, and salsa to the bowl, and whisk well. Set aside.
Heat the oil in an oven safe sauté pan** on medium low heat. Add the leeks and onion and sauté for 2-3 minutes until they become soft and slightly brown. Then add the broccoli, and sauté for an additional 3 minutes (until it turns bright green and mostly cooked).
Add the garlic, herbs and salt, and cook for an additional minute.
Keeping the pan on medium low, add the egg mixture. Using a spatula or wooden spoon, mix the frittata mixture as if you were going to scramble the eggs. You want them to start cooking to reduce the time in the oven. Stir for about 1 full minute, then turn off the heat.
Place the sliced tomatoes on top of the frittata, and sprinkle with the remaining cheese.
Place in the oven, and cook for 25-35 minutes, depending on the depth of your pan. The frittata is cooked when the egg on top is cooked through.
Let cool for a few minutes, and then enjoy!
** If you don’t have an oven safe pan, follow directions through Step 4. Then, add the frittata mixture to an oven safe baking dish. Place the tomatoes and remaining cheese on top, and cook for 25-35 minutes.