1. Place the onion, garlic, parsley sprigs, and bay leaf in a double layer of cheesecloth and tie it shut.

2. Place the lentils in a medium-size saucepan and add enough cold water to cover them by 3 inches. Bring to a boil over high heat. Skim the foam off thoroughly, add the cheesecloth bag, and reduce the heat to low. Simmer until the lentils are tender, 15 to 18 minutes. Drain the lentils. (If you are making the lentils ahead, toss them with a little olive oil. They will keep for up to 2 days, covered, in the refrigerator. Let them come to room temperature before continuing with the recipe.)

3. Heat 1 tablespoon olive oil in a medium-size skillet over medium-high heat. Add the chorizo and cook, stirring, until nicely browned and beginning to crisp, about 5 minutes. Using a slotted spoon, transfer the chorizo to paper towels to drain and keep warm.

4. Pour olive oil to a depth of ½ inch in a small skillet and heat over medium heat until almost smoking. Add the ham slices, one at a time, and cook until shriveled and crisp, about 30 seconds, transferring the cooked slices to paper towels to drain.

5. Place 3 tablespoons olive oil, the sherry vinegar, red wine vinegar, chicken stock, and honey in a small microwave-safe bowl and stir to mix. Microwave on high power for 30 seconds, then season the vinaigrette with salt and pepper to taste.

6. Place the drained lentils, chorizo, tomatoes, chopped parsley, scallions, and warm vinaigrette in a large bowl and toss to mix. Crumble the crisp ham slices into medium-size pieces, toss some with the salad, scatter the rest on top, and serve.