Lentil and Spring Greens Salad with Cranberry Apple Cider Vinaigrette

In a heavy saucepan, cover lentils with water by 2 inches and simmer until just tender but not falling apart, about 15 minutes. Drain lentils well in a sieve. Rinse lentils under cold running water to stop cooking and drain well. Skip this step if using already-cooked lentils.

In a bowl, toss lentils with 2 tablespoons vinegar and salt and pepper to taste. (Lentils may be made 2 days ahead and chilled, covered. Bring lentils to room temperature before proceeding.)

In a skillet, cook pancetta over moderate heat until crisp.

In a saucepan, heat 2 tablespoons oil over moderate heat until hot but not smoking, and cook shallot, stirring, until golden brown. Stir in water, cranberries, sugar, and remaining 5 tablespoons vinegar and simmer, stirring occasionally, until liquid is reduced by about half, about 10 minutes. Reduce heat to low and whisk in remaining 2 tablespoons oil in a slow stream until emulsified. Season vinaigrette with salt and pepper.

Add half of vinaigrette to lentils and toss well. In another bowl toss spring greens with half of the lentil mixture, half of the pancetta, half of the cheese, remaining vinaigrette, and salt and pepper to taste.

Divide remaining lentil mixture among 6 plates and top with spinach mixture. Sprinkle salads with remaining pancetta and cheese.