In a large saucepan, bring water to a boil. Cook penne pasta according to package directions.
Meanwhile, heat olive oil in a large skillet over medium-high heat. Add in onions and mushrooms. Season with salt and pepper and saute for about 5 minutes.
Add in the minced garlic and saute for another minute.
Add in the vinegars. It'll sizzle like crazy and reduce rather quickly.
By this time your pasta should be done and drained. Turn off the heat and add in the cooked pasta, cherry tomatoes and spinach. Stir to coat the noodles and continue until the spinach begins to wilt. It should only take a minute or two. Taste, and season with more salt and pepper if necessary.