Mushroom Galette Recipe

Name: Mushroom Galette Recipe
Prep time: 15 min
Cook time: 25 min
Total time: 40 min
Cuisine: French
Ingredients: 1 sheet of pie dough; 1/3 cup whole milk ricotta; 6 oz. crimini mushrooms, cut into slices; 1/4 of a jumbo white onion, cut into thin crescent-shaped slices; 1.5 oz gruyere cheese, shredded; parmesan cheese, for grating as a garnish; pinch of salt and freshly ground pepper; pinch of nutmeg; 1 egg, separated into white and yolk; olive oil; 1 sprig of thyme