Fennel

Want firm, plump, white-to-pale-green bulbs with tightly layered, unblemished layers and crisp, bright-green fronds (a sign of freshness) if attached. Avoid bulbs that are browning, splitting, dried-out, or have flowering stalks, which signal it's old and woody. Squat, rounder bulbs are often more tender than long, flat ones.

Fresh fennel bulb (hinojo) is seasonal and not always stocked in Spanish supermarkets — fennel seed (semilla de hinojo) is the more reliably available form. Keep the bulb in the crisper, loosely bagged, for up to a week or so; trim the long stalks but save the fronds. To prep, cut off the stalks, trim the base, halve through the core, and remove the tough triangular core if cooking in wedges (keep it to hold the layers together for roasting). Slice across the bulb for thin shavings.

Raw, fennel is all crunch and bright licorice — shave it wafer-thin on a mandoline, dress with lemon and oil, and it's a refreshing salad, especially against citrus and rich fish. Cooked, it transforms: roasting, braising, or caramelizing tames the anise into a soft, sweet, almost onion-like mellowness. Both modes are worth knowing.