2 large onions (about 1 1/2 lbs.) sliced thinly
2 tbsp olive oil
1/2 lb. Gruyere cheese shredded (about 2 cups)
1/2 lb. plum tomatoes cut into 1/2 inch wedges
1/2 lb. medium yellow tomatoes (or 1/2 lb. plum tomatoes if yellow tomatoes are not available) cut into 1/2 inch wedges
1/4 cup Nicoise olives, pitted
One recipe for butter pastry dough (I used the Pillsbury prepared pie crust dough from the refrigerated section in the grocery and it worked just as well)
Butter Pastry Dough
2 cups all-purpose flour
1 1/2 tsp salt
1 1/2 sticks cold unsalted butter cut into bits
6 – 7 tbsp ice water.
In a large heavy skillet cook onions with salt to taste in oil, covered over moderate heat, stirring occasionally, until softened, about 20 minutes (I added 1 tbsp fresh thyme leaves and it was amazing). Remove lid and cook onions, stirring occasionally, until golden and any liquid evaporates. Remove skillet from heat and cool onions slightly.