A cue from Jose Andres' Made in Spain...great little book: you should pick up a copy.
Puy or French lentils
Green and red bell peppers
In a large pot of water, bring lentils, onion (leave in large chunks), garlic, bay leaf, and a small amount of olive oil to boil. Meanwhile, small dice the peppers and tomatoes and chill.
Cook the lentils until tender. Strain lentils, removing aromatics, but reserving cooking liquid. Add the lentils to the peppers and tomato, and continue to chill. Reduce the reserved, flavorful liquid by about 1/2.
Once the lentils are cool, dress with vinegar, shallots and oil. Garnish with chives and cheese.