Creamy Mushroom and Spinach Pasta

I'm sure most of  you finding my recipes found me through Pinterest. I have a board called, "Food I've Gotta Make." I'm forever pinning recipes that look really, really good. Well, let me back up, pictures that look really, really good. Sometimes the recipes are "meh" and sometimes they're keepers. Go ahead and add this one to your keepers stack.
The original recipe on Pinterest is here. I did make a few tweaks to it, but nothing really earth-shattering. It was delicious! It's vegetarian! Not that we are vegetarians, but we do make an attempt to eat healthy...healthier from time to time. There are a lot of steps, but they're easy. A beginner can make this and impress someone. The taste is delish!!! My only gripe is I have to use two skillets. An extra large to build the sauce in and another to saute the mushrooms.

INGREDIENTS:
3 large sweet onions chopped
16 oz. Portobella mushrooms sliced
Small bag spinach (about 5-6 oz.)
1 box Dreamfields spaghetti
2/3 cup heavy cream
1/3 cup milk
1 cup shredded Parmesan cheese
1 tbsp. balsamic vinegar
Olive oil
Salt for seasoning

 In your extra large skillet, carmelize your onions. Heat 1 tablespoon of olive oil, add onions and cook on high for 6 minutes. Stir, stir, stir!! Add a little salt, turn heat down to medium and continue to cook.

 In another skillet, heat a tablespoon of olive oil and begin cooking your mushrooms. Add a little salt and let them cook for around 15-20 minutes. Turn them periodically.

 Let's get back to the onions. The edges are going to start to turn a little brown on some of them. Add the balsamic vinegar and stir. I cooked these for a total of 20 minutes.

 Add the cooked mushrooms to the onions and blend well.

 Stir in the spinach by handfuls and let it wilt. As it cooks down, add more. At this point, start the water for your pasta and cook per the directions on the box.

In the skillet with the veggies, add the cream, milk, Parmesan cheese and salt to taste.

Let this heat on medium low. Blend well.

Once the pasta has been cooked and drained, add it to the sauce.

Serve in a bowl (or plate) and top with shredded Parmesan cheese.