Prepare spaghetti squash according to recipe. Cover then set aside.
Place skillet over medium heat then add olive oil. When oil is hot, add onion and bell pepper. Cook 2–3 minutes—until the onion begins to soften—then add mushrooms, salt and pepper. Continue cooking for about 3–4 minutes, stirring frequently. Add garlic, cook for 1 additional minute then remove from heat.
Drain any liquid that may have accumulated in the bottom of the bowl of spaghetti squash then add the sautéed vegetables and toss with spaghetti squash to combine. Season to taste with salt and pepper.
Transfer to a serving dish then sprinkle with feta cheese and chopped parsley. Enjoy!
Notes
Spaghetti squash is low in calories averaging about 42 calories in a 1 cup serving—woot woot!