This recipe is so easy to make! You can have a delicious meal on the table in just 40 minutes with a simple marinade and a quick bake in the oven.
Set the mushrooms top side down and pour the remaining marinade over them. Place the skillet in the oven and bake for about 20 minutes.
After the initial baking time, flip the mushrooms and asparagus, and bake for an additional 5-10 minutes.
While the mushrooms and asparagus are baking, prepare a side of mashed potatoes.
Once everything is cooked, serve your portobello mushroom steaks and mashed potatoes immediately for the best taste and texture.