Penne pasta with "creamy" tomato sauce

We just discovered a couple really awesome pasta recipes that are really easy. There's not a lot of marinara in this one but it's still really creamy--just not from any cream! It uses Greek yogurt instead (which is high in protein, in case you didn't know).

Ingredients:

• 12 oz. ww penne pasta
• 1 T. oil
• 4 cloves garlic, minced
• 1 pinch crushed red pepper flakes
• 8 oz. button mushrooms, sliced
• 2 medium tomatoes, chopped
• S+P to taste
• 4 c. fresh spinach
• 1/2 c. marinara sauce
• 1/3 c. fat free plain Greek yogurt
• 1/4 c. grated parmesan cheese

Cook pasta according to directions.

In large skillet with lid, heat oil on med-low heat. Add garlic and red pepper flakes and cooked about two minutes or until garlic begins to soften. Add in mushrooms, tomatoes and S+P. Cook 5 minutes or until mushrooms release their water. Remove from heat and add in spinach. Let wilt for 2 minutes with lid on. (The spinach won't look very wilted, but by the end of the next step it will). 

Remove lid and place skillet back over low heat. Add the penne, Greek yogurt and pasta sauce. Stir until sauce is mixed and everything is coated. Heat until warmed through. Serve warm topped with parmesan cheese. 

p.s. this is also on my pinterest page if any of you are on there and want to see a picture. ours was devoured before we snapped a pic.