Preheat the oven to 375°F (190°C).
Clean the mushrooms and remove the stems.
In a skillet, heat olive oil over medium heat and sauté garlic until fragrant.
Add chopped spinach and artichokes; cook until spinach wilts and moisture evaporates.
In a bowl, mix together cream cheese, mozzarella, Parmesan, sautéed spinach and artichokes, lemon juice, salt, and pepper.
Fill each mushroom cap generously with the mixture.
Place stuffed mushrooms on a baking sheet lined with parchment paper.
Bake for 20-25 minutes, or until mushrooms are tender and the tops are golden.
Let cool for a few minutes before serving.