1 head garlic
3 tablespoons olive oil, divided
3 cups water plus 2 tablespoons divided
8 slices stale bread
4 cups halved and thinly sliced leeks, white and green parts
½ teaspoon sea salt, divided
1 cup shredded Gruyere cheese
1 tablespoon chopped fresh thyme
¼ teaspoon freshly ground black pepper
1. Preheat oven to 3745 degrees.
2. Remove outer skin from garlic and place the heads in a small baking dish. Drizzle with ½ teaspoon olive oil. Add ¼ inch water to the dish. Roast, uncovered, until tender, but still firm, about 30 minutes. Let cool slightly then peel the cloves. Thinly slice and set aside.
3. Meanwhile, bring 3 cups water to a boil. Place bread in a shallow heatproof dish large enough to hold a single layer. Pour in enough water to submerge it. Let stand until bread is saturated, 3-5 minutes. Transfer the bread to a colander in batches and gently press out the liquid. The bread should be somewhat moist, but not dripping. Tear it into irregular pieces and transfer to a large bowl.
4. Heat 1 tablespoon oil in a large skillet or Dutch oven over medium heat until shimmering. Add leeks, 2 tablespoons water, and ¼ teaspoon salt, partially cover and cook, stirring occasionally, until leeks are tender, but still bright green, about 5-7 minutes.
5. Add the leeks to the bowl of bread along with the sliced garlic, 1½ tablespoons oil, cheese, thyme, pepper, and remaining ¼ teaspoon salt; gently combine with your hands or a spoon. Spread the mixture into a shallow baking dish large enough to hold it in a 1-inch layer, such as a 9×13 inch pan. Drizzle with the remaining 1 teaspoon oil.
6. Bake until crisp and golden in spots, about 30 minutes. Serve warm.
Serves 6, about ¾ cup each