Preheat oven to 250°F. Line baking sheet with parchment paper.

Stir together potato, horseradish, mayo, shallots, lemon zest, chives, salt, and pepper.

Season fish with salt and pepper. Pat a thick layer of crust mixture on each fillet.

Generously grease a large sauté pan with evoo and place over medium-high heat.

Place fillets, crust-side down, in the pan and brown for 3 to 5 minutes. Don't touch or move them until the crust starts to turn golden-brown ad caramelized around the edges.

Once browned, remove fish and transfer to prepared pan.

Before serving, cook fish in a 250°F oven for 30 minutes. 

Chef's tip: slow roasting fish allows the natural fats in the fish to melt and baste the fish. This will yield a really juicy and moist fillet. You can also pre-cook fish and just gently warm it before serving. a thick fillet will not dry out if heated very gently.

Garnish with chive oil (recipe below).

In a food processor, or by hand, whisk yolks, honey, garlic, anchovies, lemon juice, salt, and pepper. 

Chef's tip: do most of your seasoning for vinaigrettes and mayonnaise before adding oil, otherwise the salt will not easily dissolve in oil and will result in an unevenly flavored sauce.

With the motor running, or while whisking like a maniac, drizzle in evoo, drop by drop, until the sauce starts to emulsify. Once the sauce begins to thicken, you can go boldly forth with adding oil.

Tweak seasoning once the sauce has formed. Store homemade mayonnaise, covered on the surface to prevent a skin from forming for up to 5 days.

Line a baking sheet with paper towels.

Heat a medium sauté pan over medium-low heat. Cook shallots and oil until shallots are medium brown and crispy, about 20 minutes.

Transfer to prepared pan and sprinkle with salt. Store shallots in a container with a tight-fitting lid at room temperature for up to 3 days.

Pour 1/4 cup evoo in a sauté pan and place over medium-high heat.

Quickly fry chives and parsley for 10 seconds. Chef's tip: frying herbs in hot oil is similar to blanching vegetables. The chlorophyll will become trapped in the cells and will make the herbs bright green.

Transfer herbs and oil to a blender of food processor. Add salt and process until a green oil is formed.

Store oil in a refrigerator in a covered container for up to 1 week or freeze for 2 months.