Wild Mushroom and Gruyère Tart with Fresh Herb Salad

INGREDIENTS

• 1/2 cup whole-milk ricotta cheese
• 1 1/2 pounds assorted fresh wild mushrooms (such as chanterelle, oyster, or stemmed shiitake), sliced
• 1/4 cup crème fraîche or sour cream
• 3 tablespoons fresh chervil leaves
• 4 ounces thinly sliced Gruyère cheese
• 6 tablespoons fresh Italian parsley leaves
• 3 tablespoons fresh tarragon leaves
• 2 teaspoons fresh thyme leaves
• 2 teaspoons fresh lemon juice
• 2 tablespoons extra-virgin olive oil
• 1 sheet frozen puff pastry (half of 17.3-ounce package), thawed
• 1 large egg yolk, beaten to blend with 1 teaspoon water (for glaze)
• 2 teaspoons plus 2 tablespoons extra-virgin olive oil
• 1/3 cup 1/2-inch pieces fresh chives
• 1 large egg yolk
• 1 bunch green onions, thinly sliced on diagonal (about 1 1/2 cups)
• 1 tablespoon butter