White Bean and Watercress Gratin
1 pound dried white beans (Great Northern or navy), picked
4 cups chopped onion
2½ quarts water
3 tablespoons olive oil
2 teaspoons white wine vinegar
1 teaspoon salt
pepper to taste
1½ cups packed tender watercress sprigs, plus additional for
1 cup fine day-old bread crumbs
1 cup grated Gruyère cheese
1 garlic clove, minced
In a kettle combine beans with enough cold water to cover them by 2
inches; bring water to a boil and simmer beans, uncovered, 2 minutes. Remove kettle from
heat and let beans soak, covered, for 1 hour.
Drain beans in a colander, return them to kettle, and stir in the
onion and 2½ quarts water. Simmer beans 35 to 45 minutes or until tender.
Drain the beans in the colander set over a large bowl and transfer
the beans to a 3-quart gratin dish or other shallow baking dish. Return cooking liquid to
the kettle and boil it 5 to 10 minutes or until it is reduced to about 1½ cups.
In a blender, purée 1 cup beans with the reduced cooking liquid,
oil, vinegar and salt and stir the purée with 1½ cups watercress into the whole beans.
(Can prepare to this point 2 days in advance and kept covered and chilled.)
In bowl toss together bread crumbs, Gruyère, and garlic. Sprinkle
topping over gratin and bake 20 minutes at 425ºF., or until bubbly and golden. Garnish
with additional watercress. 6 to 8 servings.