ABOUT THIS RECIPEBitter Leaves, Bright Citrus
Radicchio gives this lunch its sturdy shape and distinctive, slightly bitter flavor. The leaves are firm enough to serve as little cups, while the lentils fill them without making the dish feel heavy. Choose a compact head with fresh, unblemished leaves. Carefully separate the leaves and save the best ones for serving; if any tear, finer pieces can go underneath the lentils. Radicchio and orange work so well together because the citrus brightens the bitterness without completely masking it.
Green lentils generally hold their shape better after cooking than red or yellow lentils, which break down more quickly. Cook them until just tender, then drain as soon as they are soft but still hold their shape. Overcooked lentils turn mushy and make the leaves difficult to fill. Let them steam-dry briefly after draining, then toss them with the vinaigrette while they are still warm: this helps them absorb the orange, vinegar and mustard. If cooking on a weekday doesn’t work for you, use ready-cooked lentils; rinse them and, if you like, warm them briefly so the dressing clings better.
The dressing is deliberately light. Orange juice and a little vinegar provide acidity, while olive oil rounds out the flavors and mustard helps bring everything together. Zest only the colored part of the peel; the white pith underneath can taste bitter. The sweetness of oranges varies, so taste the dressing before adding it to the lentils. A tart orange may call for a little more oil, while a sweet one can benefit from an extra splash of vinegar.
Crumbled soft goat cheese adds creaminess and a fresh, slightly tart contrast. For a milder flavor, you can use feta, though it is saltier and firmer. Pumpkin seeds toast quickly in a dry frying pan: stay nearby and take them off the heat as soon as they smell fragrant and turn lightly golden. Sunflower seeds are a practical substitute. Sprinkle the seeds over the salad just before eating so they stay crunchy.
Serve the leaves as soon as they are filled, either on their own for lunch or with a slice of hearty bread. You can cook the lentils ahead and keep them covered in the refrigerator; cool them promptly and use them within three to four days. Store the dressing, cheese, seeds and radicchio leaves separately, and assemble the salad just before serving. That way, the leaves stay firm and the toasted seeds stay crisp.