Pear and Tomato Salad

Make Vinaigrette Dressing.

Core heads of lettuce. Rinse, drain, and pat leaves dry with paper toweling. Place on large plate; refrigerate, covered with clean kitchen towel, until serving time.

Stir lemon juice into large bowl of cold water. Cut pears in half lengthwise; core. Place pears in acidulated water until serving time.

Arrange onion and tomato slices, slightly overlapping, in parallel rows on each of 12 salad plates; allow about 1/2 tomato and 3 slices onion per serving. Arrange lettuce leaves, dividing evenly, on rim of plate opposite tomatoes.

Lift pears from acidulated water; pat dry with paper toweling. Cut pears into 1/4-inch lengthwise slices; divide slices evenly among the 12 plates, arranging them, slightly overlapping, in a row between the tomato slices and lettuce leaves.

Whisk vinaigrette; drizzle each salad with about 1 tablespoon of the dressing. Serve at once.