1 fennel bulb, sliced into rings, fronds reserved for garnish

1 TBSP extra-virgin olive oil, plus additional to finish

1 4-lb skin-on fillet of salmon

3/4 tsp kosher salt

1/4 cup whole-grain mustard

3 tsp fennel seeds, toasted and crushed

2 1/2 tsp coriander seeds, toasted and crushed

Preheat the oven to 300 degrees F.

Place the slices of fennel in the middle of a rimmed baking sheet and drizzle with the olive oil. Place the fillet of salmon skin-side down on top of the bed of fennel and sprinkle it with the salt. Spread the mustard evenly over the top of the salmon and sprinkle with the fennel and coriander seeds. Press gently to help the seeds adhere.

Roast until a fork inserts easily in the thickest part of the fish and the flesh flakes, approximately 1 hour. Remove the salmon to a platter. Sprinkle with the fennel fronds and drizzle with olive oil.