Preheat the oven to 400°F and lightly grease an oven-safe skillet or baking sheet.
Use a clean, damp kitchen towel to wipe away dirt or debris from the mushrooms. Carefully remove stems, leaving mushroom caps whole. If necessary, use a small spoon to gently scoop out any remaining stem so you have enough space for the filling. Arrange mushrooms, cut side up, into an even layer on the skillet or baking sheet.
Press the thawed spinach to thoroughly drain excess liquid. Add drained spinach to a large mixing bowl along with the soup, artichoke hearts, 1/2 cup of the Parmesan cheese, cream cheese, garlic, and a pinch of sea salt and pepper. Stir to thoroughly combine. Use a tablespoon measure to transfer a generous scoop into each mushroom. Sprinkle the stuffed mushrooms with remaining shredded Parmesan.
Bake for 12 minutes, or until mushrooms are tender and topping is crisp and golden.
This nutritional information refers to each serving of the entire recipe and not just the products used as ingredients.