Fried Onion Rings

Cut onions crosswise into 1/2-inch-thick slices and separate slices into rings, reserving small inner rings for another use if desired.

Stir together buttermilk, 2 teaspoons salt, and 1 teaspoon pepper in a large bowl, then gently stir in onion rings.

Let stand, turning occasionally, 10 minutes.

Drain in a colander.

Whisk together flour, remaining 2 teaspoons salt, and remaining teaspoon pepper in a wide shallow bowl. Dredge onion rings a few at a time in flour, shaking off excess, and arrange in 1 layer on wax-paper-lined trays.

Let onions stand 15 minutes (for batter to set).

Preheat oven to 200°F.

Melt enough shortening in a deep 10- to 12-inch heavy skillet to measure about 1 inch and heat over moderately high heat until it registers 360°F on thermometer. Fry onion rings in batches of 4 to 6, without crowding, turning over once or twice, until golden, about 3 minutes per batch.

Transfer as cooked to paper towels to drain, then transfer to 1 or 2 large baking sheets (overlap rings slightly if necessary) and keep warm in oven while frying remaining batches. (Return oil to 360°F between batches.)

Serve immediately.