Summer Zucchini Galette

Ingredients (12)

• 2 medium summer zucchini squash
• 1/2 15- oz. package rolled refrigerated unbaked piecrust
• 3/4 cup ricotta cheese
• 3/4 cup Parmesan cheese
• 1 cup shredded mozzarella cheese
• 1 clove garlic
• 1 Tbsp. olive oil
• 2 tsp. finely shredded lemon peel
• 1 Tbsp. lemon juice
• Salt and pepper to taste
• 1 egg yolk
• Fresh herbs