FOR THE VEGGIES:
1 tablespoon olive oil
½ of a medium red onion, chopped
1 large red bell pepper, chopped
¼ teaspoon fine sea salt
3 cloves garlic, minced
1 (5 ounce) package fresh baby spinach leaves
⅓ to ½ cup sun-dried tomatoes, patted dry and chopped (to taste)*
FOR THE EGG BASE:
12 large eggs
⅓ cup unsweetened plain almond milk
½ teaspoon fine sea salt
¼ teaspoon pepper
Preheat the oven to 350ºF. Generously grease a 9x13 inch baking dish with nonstick spray and set aside.
Add the olive oil to a large skillet set over medium heat. When hot, add in the onion, bell pepper and salt and cook for about 5 to 7 minutes, until tender. Stir in the garlic and cook for 30 seconds, until fragrant.
Working in batches, add in the spinach and cook until wilted. Remove from the heat, then stir in the sun-dried tomatoes. Taste and season with additional salt as needed.
In a medium-large bowl, whisk together the eggs, milk, salt and pepper until well combined and smooth.
Transfer the veggie mixture to the prepared baking dish and spread evenly, then pour the egg mixture over the top.
Bake for about 25 to 30 minutes, until the eggs are cooked through, set and appear puffed (the center should also only jiggle just a tad if you give it a gentle shake).
Remove from the oven and let cool for about 10 minutes before digging in. If you run a butter knife gently around the edges, the egg slab will release easier from the pan.
Source: https://cooknourishbliss.com/2020/01/15/dairy-free-frittata/