Preheat your oven to 375°F (190°C).
In a medium skillet, heat the olive oil over medium heat.
Add minced garlic and sauté until fragrant, usually about 1 minute.
Toss in the fresh spinach, cooking until it wilts down – which should take 2-3 minutes.
Incorporate the feta cheese, cream cheese, red pepper flakes, salt, and pepper into the skillet. Stir well until the cheeses meld together.
Drizzle the Portobello mushrooms with a touch of olive oil.
Evenly distribute the spinach and feta mixture among the mushroom caps.
Place the stuffed mushrooms on a baking tray.
Bake for 15-20 minutes or until the mushrooms are tender and the stuffing is slightly golden.
Once out of the oven, give them a dash of fresh lemon juice for a zesty finish.
TIPS FOR PERFECT SPINACH AND FETA STUFFED PORTOBELLO MUSHROOMS
Always clean mushrooms with a damp cloth rather than running them under water – they can absorb a lot of moisture.
For added texture, throw in some crushed walnuts or pine nuts to the stuffing mix.
If you want a crispier top, broil the stuffed mushrooms for an additional 2-3 minutes after baking.