Simple, rustic and delicious!

Serves 2 as a main course and 4 as a side

5 tbsp extra virgin olive oil
6 cups thinly sliced onions, (about 1&1/2 lbs)
1 tbsp fresh thyme leaves, divided
1 tbsp unsalted butter
1&1/4 lbs yukon gold potatoes, peeled if you want
1/2 cup heavy cream
2&1/4 lbs ripe tomatoes
3/4 cup grated parmesan cheese
1/2 cup shredded basil
4 cloves garlic, minced
Kosher salt and ground pepper

Heat a large saute pan or Dutch oven over high heat for 2 minutes
Add 3 tbsp olive oil, then the onions, 1 tsp thyme, 1 tsp salt and freshly ground black pepper.
Cook for 6 minutes, stirring often then turn down the heat to medium.
Add the butter and cook for 15 minutes, stirring and scraping with a wooden spoon until the onions start to caramelize. Turn the heat down to low and continue to cook the onions for another 10 mins or so, stirring often until the onions are a deep caramel color. Remove the pan from the heat and set aside.

Preheat the oven to 350 F

Use a mandolin to slice the potatoes into 1/8 inch rounds. Toss them with the cream, 1tsp thyme, 1 tsp salt and ground pepper.
Cut the tomatoes into 1/4 inch slices and arrange on a plate and season them with salt and pepper.

Place half the caramelized onions evenly on the bottom of a 9 x 9 inch gratin or baking dish.
Arrange one layer of potatoes on top of the onion layer and sprinkle with 1/3 of the cheese and half the garlic.

Arrange a layer of tomatoes on top of this, then sprinkle 1/2 of the basil, 1/2 tsp thyme, salt and pepper, and drizzle 1 tbsp cream from the potatoes

Scatter the rest of the caramelized onions over this mixture, arrange another layer of potatoes, then top with 1/2 of the remaining cheese and remaining garlic.

Arrange another layer of tomatoes (attractively) over the potatoes. Pour remaining cream from the potatoes over the tomatoes. Season with salt and pepper, remaining thyme and basil.

Press the vegetables down with your fingers. The cream should come up through the layers and coat the vegetables evenly.
Sprinkle with any remaining cheese.

Cover the baking dish tightly with foil and bake for about 2 hours or until the potatoes are tender when pierced.

Remove the dish from the oven, uncover it, turn the oven up to 450 F and put it back in for about 25 to 30 minutes more until the juices have thickened and the tope is browned and bubbly