While I love creamy, soft sliced potatoes layered with cheese and cream, I have also learned to love simpler, healthier potato gratins. This gratin is full of rustic flavor without the need for heavy cream since it relies on vegetables, fresh herbs, and cheese for its zesty taste.
This light, colorful gratin can be made year-round. Just substitute canned diced and drained tomatoes if fresh tomatoes are not at their prime. Look for the organic canned variety that have extra flavor and a deep red color.
You can make up the vegetable mixture the day ahead and then finish the gratin the day you are serving it. The Mediterranean-style vegetable filling of tomatoes, zucchini, sweet bell peppers, and fresh, fragrant herbs adds a burst of flavor to the simple sliced potatoes.
You can use either Idaho potatoes that have a fluffy consistency or the creamier yellow potato. Either will work just fine. I have tested many potato gratin recipes, and I have found they key in cooking them completely is to cover the casserole tightly with foil, so they steam. Then the foil is removed, and the potatoes, vegetables, and cheese continue to bake, creating a cheesy crust.
There are different cheeses you may prefer; sometimes I mix Emmenthaler with Comté or Gruyère. You could opt for smoked mozzarella, Gouda, or fontina.
This is so good on its own or served as a side for egg dishes, seafood, chicken, or meat.
Potato-Vegetable Gratin
Serves 6 to 8
- 3 tablespoons olive oil
- 1 leek, white and light green part only, cleaned and finely chopped
- 1 yellow bell pepper, seeded and thinly sliced
- 3 medium zucchinis, thinly sliced
- 4 medium tomatoes, peeled, seeded, and coarsely chopped
- 2 garlic cloves, minced
- Salt and freshly ground black pepper
- 1 teaspoon finely chopped fresh thyme
- 4 tablespoons finely chopped fresh basil
- 3 medium baking or Yukon Gold potatoes, peeled and sliced 1/4-inch thick
- 1 cup freshly grated Gruyère cheese
Preheat the oven to 400 degrees F. Coat a deep 3-quart baking dish with nonstick cooking spray.
Heat olive oil in a large skillet over medium heat. Add chopped leek and sauté until soft, 4 to 5 minutes. Add yellow bell pepper and zucchini and sauté until soft, about 3 to 5 minutes longer. Add tomatoes and sauté until excess liquid evaporates, 3 to 5 minutes. Add garlic, salt, pepper, thyme, and 2 tablespoons basil and mix well. Remove from heat.
Place half of the potatoes in the dish, overlapping the slices. Spread half of the vegetable mixture over potato slices. Sprinkle 1/2 cup of the Gruyère evenly over vegetables. Cover cheese with remaining layer of potatoes, then vegetables, and then cheese. Cover tightly with foil.
Bake for 45 minutes. Remove foil and bake until potatoes are tender, and top is browned, 30 to 35 minutes longer. Serve warm sprinkled with remaining 2 tablespoons basil.
Advance preparation: This dish can be prepared up to one day ahead, covered, and refrigerated. Bring to room temperature, cover with foil, and reheat in a 350 degrees F oven for 20 to 30 minutes.
