Vegetarian Stuffed Mushroom Recipe (Button or Baby Bellas)

Ingredients

• 18 medium mushrooms (destemmed and stems diced)
• Cooking spray
• 2 tablespoons olive oil
• ¼ cup small onion (minced)
• 2 garlic cloves (minced)
• ½ cup walnuts (chopped)
• 4 sprigs fresh thyme (cleaned, chopped)
• ½ cup can chickpeas
• ½ cup Parmesan cheese (divided)
• 1 tablespoon parsley (chopped)
• 2 teaspoons balsamic vinegar
• ¼ teaspoon salt (plus more for salting the mushrooms)
• ¼ teaspoon black pepper