On a lightly floured surface, roll dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim to 1/2 in. beyond rim of plate; flute edge. Refrigerate 30 minutes. Preheat oven to 425°. Line unpricked crust with a double thickness of foil. Fill with pie weights, dried beans or uncooked rice. Bake on a lower oven rack until edge is light golden brown, 15-20 minutes. Remove foil and weights; bake until bottom is golden brown, 3-6 minutes longer. Cool on a wire rack. Reduce oven setting to 350°., In a large skillet, melt butter over medium heat. Add onion, mushrooms and squash; cook and stir until tender, 3-5 minutes. Add spinach and garlic; cook 1 minute longer. Spoon into crust; top with cheese. , In a large bowl, whisk eggs, cream, salt, rosemary and pepper until blended; pour over filling. Cover edge of crust loosely with foil. Bake until a knife inserted in the center comes out clean, 40-45 minutes. Let stand 10 minutes before cutting.