Honey Balsamic Mushrooms and Spinach on Polenta topped with Caramelized Onions

Of course my first instinct when making this was to top off the polenta/spinach/mushrooms with cheese, but I’m so glad I used caramelized onions instead. This dish has the creamy polenta, sweet and tangy mushrooms and spinach from the honey and balsamic vinegar, but the caramelized onions add just an extra oomf. This meal was so satisfying and felt like something I would order at a restaurant. If it weren’t for the caramelized onions, it would even be a quick meal to make. I’ll include some options below, in case you do not have the hour to make this dish all in one clip, because this is a meal that everyone should definitely make!

Options, Tips and Substitutions!

Before you start making this recipe, take a look at the polenta you are using to determine at what point you want to start reheating or cooking your polenta. You can use a pre-cooked option or make from a package of polenta mix. If using a pre-cooked log shape polenta like I did, you can keep it more firm and structured or add water and make it into a more porridge-like consistency. I liked that the log polenta is creamy but also firm enough that it holds it circle shape. I cut the log into 12 even pieces and reheated them on the stovetop since that was the fastest way. I started reheating my polenta while I was sautéing the mushrooms and spinach.
The Caramelized Onions is what takes the longest time to cook. If you’ve never made them before, they are not necessarily difficult to make, but a bit time consuming. This is because they cook on low heat for a long time. The good news is they can be made in advance. They refrigerate and reheat nicely. That’s the first option if you do not have an hour all at once. They can even be made a few days in advance then refrigerated in an airtight container.
Another option is that you may be able to purchase caramelized onions already made.
Around 20-25 minutes, or when the bottom of the pan is dry, you will add water a tablespoon at a time. When you add the water it will sizzle and the added liquid will help remove any of the browning onion stuck to the bottom of the pan. It will also begin giving the onions a more brown/caramel color. You don’t want too much liquid in the pan, but anytime the pan has no liquid, add just a Tbsp. and then stir.
Around 30-35 minutes, the onions will be fully cooked and tender, but will most likely be a very pale/light color. You could use them at this point, however, if you want them to be darker and more caramelized, they will need an extra 15-20 minutes more. I cooked the ones in the pictures for 45 minutes and made them 2 days in advance then reheated them in the microwave.
You can use sliced or whole mushrooms and white or Baby Bella mushrooms. I used whole white mushrooms and then sliced them myself before sautéing them in the balsamic/honey sauce.
As soon as the mushrooms are browned, tender and cooked through (about 5-7 minutes), it’s time to add the Spinach. You might need to add in batches depending on the size of your pan, as the spinach cooks it will shrink a lot. It will also cook very fast about 1-2 minutes. As soon as all the spinach is soft, you will want to remove it from heat so it does not burn or begin releasing too much water and become soggy.
I know I keep mentioning this, but because I made the carnalized onions in advance, the time it took to make the mushrooms, spinach and polenta was less than 20 minutes so it was actually a pretty fast meal!