Remove stems from button mushrooms and set aside mushroom caps. Finely chop the stems. In a pan, heat the olive oil over medium heat, add the shallots and sauté until translucent, about 1 1/2 min. Add garlic and mushroom stems to the shallots and continue to sauté until soft, about 2 min. Remove from heat and fold in the cilantro and lemon juice. Season with salt and pepper to taste. Place the caps on a baking sheet with the hollow sides facing up. Place the mozzarella cube in each cap and cover with 1/2 tsp. of the stem and shallot mixture. Lightly spray the caps with olive oil spray, bake until cheese is melted and mushrooms are golden brown. Remove from oven sprinkle with parsley and serve warm
