In a small bowl, mix together all sauce ingredients and set aside.
Mince 4 cloves of garlic and saute in 1 tbsp of olive oil for a couple of minutes.
Add 3/4 cup thickly sliced red onion and saute a few more minutes.
Add 12 oz of cooked pasta (and meat, if desired) and saute 5 more minutes until pasta starts to lightly brown.
Add spinach, tomatoes, and sauce mixture and salt and pepper as desired. Saute 5 minutes or until spinach starts to wilt. (tomatoes on the vine, roma, or campari)
Remove from heat and sprinkle with parmesan or feta.