Caramelized onion and Cauliflower Tart - Bon Appetit

Start by prebaking a 9" pie crust.  Peel, cut in half and slice thinly a large white onion.  Cara-melize the onion by heating it over medium heat in a saute pan with 3T olive oil.  Cook until the onion developes a light golden brown color, about 20 min.  While the onion is cooking, divide a 1 lb head of cauliflower into small flowerettes.  Place them on a cookie sheet, drizzle with olive oil and bake at 425 degrees for about 30 min, until slightly browned.  You will have to turn the cauliflower occationally over the 30 min cook time.  When the pie crust is done, brush it with 2T Dijon mustard.  Spread the onions and then the cauliflower over the bottom of the crust.  Pour on a mix of 1/2C whipping cream, 2 beaten eggs, 1 C grated Gruyere cheese and salt and pepper to taste.  Sprinkle with Parmesan cheese and bake in a 350 degree oven for about 40 min and then allow the tart to cool for 10 min before slicing.  Serve with a green salad and a dry white wine.