I rarely say this, but this is one of those recipes that tastes even better the second day. Why? Because the mushrooms and spinach soak up all the flavors from the balsamic dressing. These stuffed portobellos with spinach are fast and very easy to make for a weeknight dinner. The meatiness from the mushrooms could easily serve as a main entrée which is perfect for a vegetarian kind of night. You could even add some chickpeas or lentils to the spinach for an extra dose of protein. There are lots of options to make these balsamic mushrooms your own.
Portobellos are so delicate. If you look closely, the bottom left one broke apart on its way home from the grocery store. Gently remove the stems. You may need to use a paring knife to remove any remaining parts of the stem.
It’s good to use a deep sided cookie sheet to catch all of the juices from the dressing so you can spoon them on top of the mushrooms after roasting. Well and the whole mess factor. Nobody wants to clean up a mess.
While the mushrooms are roasting, you can go ahead and multi-task a bit by sautéing the spinach.
The spinach is sautéed with shallots, tomatoes, and garlic along with some red pepper flakes and a drizzle of balsamic vinegar. See how this is starting to pair up now with the mushrooms?
Pine nuts are totally optional. I get it. They’re pricey. Let these mushrooms and spinach marry together in perfect flavor harmony for an even better next day meal.
This is one of those dishes that is even better the second day. The mushrooms and spinach absorb all of the flavors from the balsamic dressing.
4 portobello mushrooms, stems removed
3 tablespoons extra virgin olive oil
3 tablespoons balsamic vinegar
2 garlic cloves, minced
1 teaspoon chopped fresh thyme
1 teaspoon chopped fresh rosemary
kosher salt and black pepper
2 tablespoons extra virgin olive oil
1 large shallot, chopped
1 garlic clove, minced
1/2 cup grape tomatoes, halved
9 cups fresh spinach leaves
kosher salt and black pepper
pinch of red pepper flakes
1 tablespoon balsamic vinegar
2 tablespoons toasted pine nuts, (see note below)
Preheat the oven to 400 degrees F.
For the mushrooms: Arrange the mushrooms, stem side up, on a lined deep-sided baking sheet.
In a small bowl, whisk together the oil, vinegar, garlic, thyme, and rosemary. Season with salt and pepper. Drizzle the dressing over both sides of the mushrooms. Bake the mushrooms, stem side up, for about 20 minutes until tender. Transfer the mushrooms to a serving plate, stem side up. Spoon the juices over the mushrooms.
For the spinach: In a large saute pan, heat the oil over medium heat. Add the shallots and cook for 2 to 3 minutes until softened. Add the garlic and cook for 30 seconds until fragrant. Add the tomatoes and cook for 2 minutes. Add the spinach in batches and cook for 3 to 5 minutes until wilted. Season with salt, pepper, and red pepper flakes. Stir in the balsamic vinegar and cook for 1 minute. Spoon the spinach mixture on top of the mushrooms, stuffing them evenly. Sprinkle with pine nuts. Season with salt and pepper to taste and serve.
Note: To toast the pine nuts, heat a small pan over medium heat. Add the pine nuts, spreading them evenly in the pan. Stir occasionally until they are slightly golden 3 to 5 minutes.