1. Preheat oven to 375°F. Line a baking sheet with parchment paper for easy clean up if desired.

2. Use a mushroom brush or paper towel to wipe the mushrooms clean. Trim and discard the ends of each mushroom stem and then remove the stem completely from each mushroom by pushing sideways on the stem in one direction and then again in the other until the stem pops loose. Set stems aside for the filling.

3. Put the olive oil in a small dish and then dip the outside of each mushroom cap into the oil before placing gill-side down on the baking sheet. Transfer to the oven and bake for 10 minutes. Chop the mushroom stems and garlic.

4. Heat a large skillet over medium heat. Transfer the butter pats from the shrimp to the skillet to melt. Once hot and bubbly, add the chopped mushroom stems and garlic. Sauté, stirring frequently, until the mushrooms start to soften, about 3 minutes. Set aside.

5. Drain any liquid from the shrimp and then chop into ¼-inch pieces. Add the shrimp to the mushroom stems, along with the cream cheese, parsley, and a generous sprinkle of salt and pepper. Mix until uniform, then remove from the heat and set aside until mushrooms have finished baking.

6. Once the mushrooms have baked for 10 minutes, flip them over. Use a spoon to stuff each mushroom with the filling and then place the stuffed mushroom back on the baking sheet, stuffed-side up. Press the filling in to really fill the caps; they should be very full. Once all the mushrooms have been filled, return the pan to the oven and bake for 20 minutes.

7. Serve immediately, garnished with extra minced parsley if desired.