01 -
Heat your oven to 400°F. Gently remove the stems from your portobello caps, keeping the caps intact. Mix 1/4 cup olive oil with balsamic vinegar in a bowl, add a sprinkle of garlic powder and sage. Let the mushrooms soak up all that goodness while you prep the rest.
02 -
Mince your garlic cloves and set aside. Give the spinach a rough chop, removing any tough stems.
03 -
Heat 3 tablespoons olive oil in a pan and let the garlic brown gently for 3-4 minutes until fragrant. Toss in the chopped spinach and let it slowly wilt down for 4-5 minutes, stirring occasionally. Season with salt and pepper until it tastes just right.
04 -
Place your marinated mushroom caps gill-side down on a baking sheet and let them roast for 10 minutes.
05 -
Flip those beautiful caps over, drain any liquid, and fill them generously with your garlicky spinach. Top each cap with about 1½ tablespoons of crumbled feta. Back into the oven they go for 20 more minutes until everything's hot and melty.