Preheat oven to 350 degrees
Take your cleaned and drained escargot and place onto a paper towel and pat dry.
Melt the butter in a large skillet with the garlic over medium heat.
Add in the escargot and mushroom caps.
Cook until tender about 15 minutes.
Whisk together the wine, cream, flour and tarragon in a small bowl.
Pour into the skillet slowly and bring to a boil, stirring occasionally until the sauce thickens about 5-10 minutes.
Remove from the skillet and place the mushroom caps in a baking dish upside down.
Spoon the escargots into the caps.
Pour the remaining sauce over the mushroom caps and into the baking dish.
Sprinkle parmesan cheese over the top.
Bake until the cheese turns golden brown about 15 minutes.