Look for squash that’s heavy for its size with thick, hard skin. Store it in a cool, dry place (not the refrigerator). Primarily, it is roasted. For a simple side: cut squash in half, scoop out seeds, and roast cut-side down at 400°F until just tender, about 30 minutes. Turn over, add a touch of butter and brown sugar, and bake for 10 minutes more.
Buy cabbage with tightly packed, crisp, shiny leaves. Keep it in a plastic bag in the refrigerator for up to one week. Cabbage can be steamed, stuffed, braised, sautéed, or served raw (remove the bitter core before cooking). For a slaw: Shred one small head and toss it with 1/2 cup mayonnaise, 1/4 cup sour cream, 1/2 teaspoon kosher salt, 1/4 teaspoon pepper, a pinch of sugar, and 2 tablespoons cider vinegar.
Ripe grapefruit are heavy for their size, with shiny, finely textured skin. Store the fruit for up to 2 weeks in the refrigerator. The juice and zest can enliven all types of sweet and savory dishes, and the fruit is delicious eaten out of hand or in salads. For a quick breakfast or light dessert: Halve and sprinkle with brown sugar, then broil until it’s beginning to brown.
Look for big, clean bulbs. Bright, feathery greenery at the top of the stalks (called fronds) are a sign of freshness. Keep fennel in a plastic bag in the refrigerator up to 5 days. Fennel is wonderful braised, roasted, grilled, sautéed, or raw. For a tangy salad: Toss 2 thinly sliced raw bulbs with 2 tablespoons each of lemon juice and olive oil, 1 ounce shaved Parmesan, and some salt and pepper.
Look for kale with richly colored, dark green frilly leaves that have a little spring to them. Keep kale in a plastic bag in the refrigerator up to 3 days. Kale is delicious sautéed and in salads and soups. To add to your favorite soup: Chop 1 bunch of kale, stir into the soup, and simmer until tender, about 4 minutes.
Look for small to medium, creamy white roots that are smooth, firm, and free of pitting. Keep parsnips in a plastic bag in the refrigerator for up to 4 weeks. Peel before cooking. Parsnips can be boiled, sautéed, pureed, mashed, or roasted. For a simple roast: Cut them into 1/2-inch-thick sticks; toss with olive oil, salt, and pepper and roast at 400º F, tossing once, until tender, 35 to 35 minutes.
Buy small, firm turnips that feel heavy for their size. (As turnips age and grow bigger, their flavor becomes less sweet and their texture woody.) Keep them in a plastic bag in the refrigerator for up to 2 weeks. Turnips can be sautéed, mashed, boiled, pureed, roasted, or shredded raw. For a creamy mash: Boil peeled turnips until tender and mash with heavy cream, butter, nutmeg, salt, and pepper.