Preheat oven to 425 F.

In small bowl, toss basil and goat cheese together and set aside.

In deep 9-inch cast iron or ovenproof skillet, heat avocado oil over medium, coating bottom and sides. Add vegetables, then lightly sauté until warmed through and colors remain vibrant. In skillet base, spread vegetables around, spacing evenly, before adding egg mixture.

While vegetables are warming up, in medium bowl, whisk eggs, milk, salt, and pepper together. Pour egg mixture slowly into skillet and cook on stovetop, without stirring, for 3 minutes.

To top of cooking egg mixture, add goat cheese evenly. Carefully remove skillet from stovetop and place in oven for 10 to 15 minutes, until eggs are set in the middle and top is beginning to brown. With an oven mitt, remove skillet from oven, loosen edges of frittata with spatula, divide, and serve!