Preheat oven to 375 F. Line a baking sheet with parchment paper and set aside.
Heat a pan over medium heat. Add the chopped spinach, onion, basil, and sun dried tomatoes. Cook for about 5-8 minutes, until the veggies are tender yet crisp. Cool the veggies for a couple of minutes so they're not too hot.
In a large bowl, whisk the eggs, Greek yogurt, seasonings, and cooked veggies together until smooth.
Mix in the almond flour, coconut flour, ground flaxseeds, and baking powder. Let the mixture sit for 5 minutes to thicken.
Using a large cookie scoop or 1/4 c measuring cup, scoop the batter onto the lined baking sheet. The batter may spread a bit, and that's ok. There will be about 10 biscuits.
Top each biscuit with a sprinkle of shredded cheese.
Bake for about 25 minutes, until firm and golden brown.
Cool completely and refrigerate any leftovers. They will keep for about 5 days in the fridge. Reheat them in the microwave for about a minute to enjoy them again! Yum!