Fennel, White Bean, and Tuna Gratin

Sunday should be sunny and a perfect day for a stroll to the Fairmount Neighborhood Farmers Market to pick up some colorful produce from Camas Swale Farm and recapture the fleeting flavors of summer.

Last week I picked up a fennel bulb, which I love to cook in a fennel and sardine pasta with lemony breadcrumbs. But then this recipe for a white bean and tuna gratin caught my fancy, because it reminded me both of a favorite white bean and tuna salad and Julia Child's salmon gratin from Mastering the Art of French Cooking, volume 1, which my mother used to cook as a regular weeknight meal. Certain of my childhood dishes don't translate well to my children's taste, who prefer bright, fresh flavors to cream sauces. I've already reengineered Julia's dish of a creamy gratin, laced with white vermouth and sprinkling of gruyere cheese, as salmon and barely cakes, but truth be told, frying patties is more work than sticking a casserole in the oven. I liked the idea of including legumes in a gratin and lightening it up with fennel and lemon. 

This is the resulting dish, packed with fragrant fennel and topped with a crunchy lemony bread crumb and gruyere crust. It was delicious eaten with kamut and roasted broccoli and red peppers, fresh from the farm.

Fennel, White Bean, and Tuna Gratin

served four

1 fennel bulb
1 small onion or 2 shallots
3 Tbsp butter
3 Tbsp flour
1 tin tuna in olive oil
1 cup milk, heated to just below scalding
1/4 cup white vermouth
juice from 1 small lemon
3 cups cooked white beans (from 1 cup dried, or 2 15 ounce cans)
salt and pepper to taste
1/2 cup grated gruyere cheese
1 cup bread crumbs
1 handful fennel fronds
zest from 1 small lemon

1. Preheat the oven to 425 degrees. Dice the fennel bulb and the onion and reserve a few fennel fronds for the bread crumb topping. Zest and juice 1 small lemon. Combine the bread crumbs, lemon zest, chopped fennel fronds, and gruyere and reserve.

2. Heat a large skillet and melt the butter. Add the diced fennel and sauté until glassy. Add the diced onion and sauté until both are very soft, about 10 minutes. Add the olive oil from the tuna tin, then add the flour and whisk into the fat. Continue whisking as you slowly add the hot milk to make a light roux. Add the white vermouth and lemon juice. Generously salt and pepper. Remove from the heat and gently fold in the white beans and tuna. 

3. Pour the white bean and tuna mixture into a 9 inch square oven proof dish. Top with the bread crumb mixture.  Bake at 425 degrees for about 30 minutes, until the mixture is bubbling and the bread crumb topping is nicely browned. Serve with whole grains such as wheat berries, barley, or kamut.