PENNE WITH GREEK YOGURT CAESAR SAUCE

Name: PENNE WITH GREEK YOGURT CAESAR SAUCE
Ingredients: * 3/4 cup hidden valley® greek yogurt creamy caesar dressing; * 1/2 lb penne pasta ((8 oz )); * 1 small onion (, diced); * 2 clove garlic (, minced); * 1 tbsp olive oil; * 15 oz can of diced fire roasted tomato; * 1/2 tsp dried oregano; * 1 pinch red pepper flake (, or to your taste); * salt and fresh ground pepper (, to taste); * 1/4 cup parmesan cheese (, grated fine); * extra parmesan for sprinkling atop finished pasta when serving; * 5 oz fresh baby spinach