Sprinkle flour over counter and roll pie crust dough to fit a 7x11-inch rectangle baking dish, making sure dough comes up the sides of the dish. Poke bottom of crust with a fork in several places. Bake for 9 to 10 minutes or until crust is lightly browned.
Remove from oven to cool. Reduce oven temperature to 400 degrees.
In a cast iron, or heavy skillet, heat butter and olive oil over medium heat until it begins to sizzle. Add onions and sugar. Saute until onions are very brown and caramelized.
Add garlic and stir constantly for another 1 to 2 minutes or until garlic is cooked through and tender. Remove onions and garlic from skillet and set aside to cool.
In the bowl of a food processor, combine the cream cheese, mayonnaise, heavy cream, sour cream, honey mustard, Parmesan cheese and green onions. Process until well mixed. transfer to a mixing bowl and set aside.
In the cooled pie crust, layer half of the following ingredients: sauteed onions, cream cheese mixture, sliced tomatoes, salt, black pepper, basil and Gruyere cheese. Repeat layering using all ingredients.
Bake 35 minutes or until pie is bubbling and top is browned.
Remove from oven and cool for 10 to 15 minutes before slicing.