1 yellow or white onion, small diced
1 red bell pepper, seeded and small diced
3-6 cloves garlic, minced
1 large spaghetti squash, cut in half lengthwise and seeded
1 lb. cooked, peeled, and deveined shrimp
2 tsp. olive oil
1-2 Tbsp. butter, sliced thinly
1/3 cup grated Parmesan cheese
salt
pepper
juice of 1 fresh lemon