Preheat the oven to 350°F and lightly grease a 2.5 quart casserole dish.
In a medium size frying pan over medium-high heat, sauté onion in olive oil for 2-3 minutes until tender.
Add the sausage, and cook thoroughly until brown and crumbly.
Stir in the minced garlic and Italian seasoning and cook for 1-2 minutes until the garlic is fragrant.
In a large bowl beat eggs until light and lemon-colored.
Add the melted and cooled butter, flour, baking powder, sea salt, and pepper. Stir to combine.
Fold in the cottage cheese, green chilis, Monterey jack cheese, and sausage mixture.
Pour the egg mixture into the prepared casserole dish and spread evenly.
Bake for 60 minutes or until a toothpick inserted in the middle comes out clean. The casserole will puff up while it's baking and settle as it cools.
Let cool for 10 minutes before slicing and serving. Garnish with fresh basil.
Store leftovers in an airtight container in the refrigerator for 3-4 days or freeze for up to 3 months.
Notes
Grease the casserole dish well to prevent sticking.
Bake until the center is fully set; it will puff, but settle as it cools.
Let the egg puff rest 10–15 minutes before slicing.
To make ahead, assemble as directed, cover, and refrigerate overnight. Let it come up to room temperature before baking or add a few extra minutes to the bake time if baking from cold.
To make individual servings, pour mixture into well-greased muffin pans, about 3/4 full and bake at 350°F for 18-22 minutes, until the centers are set and the edges are pulling away from the pan.