Butternut Squash Gratin

Ingredients:
2 leeks, chopped
3-5 TBS olive oil
5 cloves garlic, chopped
1 tsp dried thyme
1/2 tsp dried sage
1 can chopped tomatoes
1 butternut squash
1/4 lb Gruyere cheese, grated

Procedure:
1. Prepare squash by cutting in half lengthwise, scooping out seeds, and cutting into thick half-circles. Heat some of the olive oil in a frying pan and fry the squash in batches until brown on both sides.
2. Sauté the leeks, garlic, and herbs until leeks are soft. Add the tomatoes and simmer for 30 minutes. Add salt and pepper to taste.
3. Spread a thin layer of the tomato sauce over the bottom of a pyrex baking dish, then a layer of squash, then a dusting of the grated Gruyere. Repeat these layers until all the squash is used.
4. Bake at 350 until the sauce bubble up through the squash and the cheese on top is browned.