Start by preheating the oven to 450F and preparing a baking sheet by lining it with parchment paper, foil or a silicon baking mat.

Next, prepare the mushrooms by carving out the center and stem. Then, brush the tops and bottoms with EVOO and season with salt and pepper. Place the portobello mushrooms center side down on the baking sheet and bake for 8 minutes.

In the meantime, prepare the stuffing. Heat 2 Tbsp of EVOO in a large skillet over medium/low heat. Add in the red onion and garlic and sauté until translucent, about 2-3 minutes.

Next, add in the sun-dried tomatoes and spinach and mix until spinach welts down. Add in the feta cheese last and mix once more. Remove from heat.

When the mushrooms are done, remove from the oven and carefully flip them over with a spatula. Then, divide the stuffing evenly amongst the mushrooms and place back in the oven for an additional 5 minutes. Remove from oven and drizzle with balsamic glaze and enjoy.

I like to serve mine with spaghetti for a complete meal. Portobello mushrooms are best stored in an airtight container in the fridge and enjoyed within 3 days.