Prepare the vinaigrette: Mix olive oil, hazelnut oil, balsamic vinegar, salt, pepper, tomato halves, and chives in a bowl. Set aside.

Prepare the white bean mash: Coarsely mash white beans with a fork.

Heat olive oil in a pan. Add diced fennel root, rosemary, and sage.

Cook the fennel mixture for 3-4 minutes, until slightly softened. Remove the rosemary and sage sprigs.

Stir in pastis, then add the mashed white beans. Mix well and season with salt and pepper.

Keep the white bean mash warm.

Preheat oven to 450°F (232°C).

Season cod fillets with salt and pepper.

Heat olive oil in an oven-safe skillet over medium-high heat.

Sear cod fillets for 1-2 minutes per side.

Flip the cod fillets and transfer the skillet to the preheated oven.

Bake for 5 minutes, or until the cod is cooked through and flakes easily.

To serve, place a cod fillet on top of the white bean mash.

Spoon the tomato vinaigrette over the cod and mash. Garnish with toasted chopped hazelnuts and fresh chives.