Heat oven to 350°F. In 10-inch skillet, melt butter over medium heat. Add mushrooms, flour, onion and garlic; mix well. Cook about 5 minutes, stirring frequently, until vegetables are tender. Add cream and cheese; mix well. Cook 2 to 3 minutes, stirring frequently, until most of liquid has evaporated.
If using crescent rolls: Unroll dough into 2 long rectangles; firmly press perforations to seal. If using dough sheet: Unroll dough; cut into 2 long rectangles.
Cut each rectangle into 12 squares. Place 1 square in each of 24 ungreased miniature muffin cups. Firmly press in bottom and up sides of cups, leaving corners of dough extended over edges of cups. Spoon 1 heaping teaspoon mushroom mixture into each cup.
Bake 9 to 12 minutes or until golden brown. Sprinkle with parsley. Cool 5 minutes. Remove tartlets from pan. Serve warm. Cover and refrigerate any remaining tartlets.