01 -
Preheat oven to 400°F. Wash and scrub each sweet potato thoroughly, then pierce several times with a fork. Arrange on a parchment-lined baking sheet and bake for 45 to 60 minutes, or until very tender.
02 -
While the sweet potatoes bake, heat the olive oil in a large skillet over medium heat. Add the diced onion and sauté for 3 to 4 minutes, until soft. Add the minced garlic and cook for 1 minute, stirring constantly. Stir in the sliced mushrooms, cooking 5 to 7 minutes until mushrooms release liquid and start to brown.
03 -
Add spinach to the skillet, stirring until just wilted, about 2 to 3 minutes. Stir in rosemary, salt, black pepper, and optional red pepper flakes. Cook for 1 more minute. Remove skillet from heat. Gently fold in feta cheese and lemon zest until evenly distributed.
04 -
Remove sweet potatoes from oven and allow to cool briefly. Slice each potato lengthwise down the center, keeping the base intact. Press the ends inward to open the potatoes. Fill generously with the mushroom, spinach, and feta mixture.
05 -
Top each stuffed sweet potato with chopped walnuts and a drizzle of olive oil for added texture and flavor, if desired. Serve immediately while hot.