Rare-Seared Tuna with Crushed Fennel

The rather aggressive seasonings for this tuna dish mimic those used to make a traditional Italian pork roast: fennel seeds and fronds, black pepper, garlic, and rosemary. They seem completely appropriate for tuna’s meaty character. Use the feathery fronds from ordinary fennel bulbs, or wild fennel if it’s available. I think this tuna tastes best at room temperature, so I usually cook it a bit ahead. As for accompaniments, a salad of cannellini beans and green beans comes to mind, as does a