This Roasted Potato, Caramelized Onion and Gruyere quiche is crustless which means there are fewer carbs since there's no floury crust. Instead, I've mixed eggs and cream together and mixed in buttery, roasted potatoes with caramelized onions that had been slow cooking on the stove. To give it a creamy, salty flavor, I stirred in pieces of delicious gruyere cheese. No crust is necessary.