1/2 pounds Brussels sprouts, trimmed and any discolored leaves discarded
2 leeks (white and pale green parts)
3/4 pound Savoy cabbage (about head), cored and sliced 1/4 inch thick
3 tablespoons extra-virgin olive oil, divided
3 tablespoons unsalted butter, divided
4 garlic cloves, finely chopped
2/3 cup dry white wine
4 cups water
1 tablespoon fresh lemon juice
1 teaspoon fresh thyme leaves, divided
3/4 pounds dried linguine
1/4 cup chopped flat-leaf parsley
Accompaniments: extra-virgin olive oil for drizzling; grated parmesan
Reserve a few outer layers of leaves from Brussels sprouts. Quarter Brussels sprouts lengthwise. Thinly slice leeks, then wash.
Cook leeks and cabbage in 2 tablespoons oil and 2 tablespoon butter with 1/4 teaspoon each of salt and pepper in a 12-inch heavy skillet (preferably with straight sides) over medium heat, stirring occasionally, until softened, about 5 minutes. Add garlic and cook, stirring, 1 minute. Add wine and simmer until most of liquid has evaporated, 2 to 3 minutes. Add water, lemon juice, 1/2 teaspoon thyme, and remaining tablespoon each of oil and butter. Simmer briskly, covered, until cabbage is tender and liquid is reduced by half, about 15 minutes. Stir in Brussels sprouts and leaves and simmer, covered, stirring occasionally, until tender, about 5 minutes.
Cook linguine in a pasta pot of boiling salted water (3 tablespoons salt for 6 quart water) until almost al dente. Reserve 2 cups pasta-cooking water, then drain pasta.
Stir linguine into vegetables with reserved cooking water and 1/4 teaspoon each of salt and pepper. Simmer until pasta is al dente, 2 to 3 minutes. Remove from heat and toss with parsley, remaining 1/2 teaspoon thyme, and salt to taste. Serve pasta in shallow bowls with some of broth.