These stuffed squash boats are cheesy, creamy, dairy-free, gluten-free, loaded with vegetables, and even low-carb! 5) Saute Spaghetti Squash: Add spaghetti squash strands and crumbled feta to pan with sauce over medium heat and stir to combine. Spread squash, tomatoes, onion, feta cheese, spinach, and spaghetti sauce in 3 even layers in a casserole dish. Top with Parmesan cheese. Heat until warmed through (about 1 min). Spinach Stuffed Spaghetti Squash This easy vegan garlic spinach and feta cheese Spaghetti Squash recipe is the best healthy and delicious comfort food for fall! Season with salt and pepper. Scrape squash flesh into spaghetti strands with a spoon; place into a bowl.