|Steelhead trout fillets||2 1⁄4 Pound, cut into 6 serving pieces|
|Vegetable oil||1 Tablespoon|
|For mint-hazelnut pesto|
|Spearmint leaves||1 Cup (16 tbs) (loosely packed)|
|Garlic||5 Clove (25 gm)|
|Pine nuts||1⁄4 Cup (4 tbs)|
|Grated parmesan cheese||1⁄4 Cup (4 tbs)|
|Olive oil||1⁄2 Cup (8 tbs)|
|Freshly ground black pepper||To Taste|
|Hazelnuts||1⁄2 Cup (8 tbs), toasted and coarsely chopped|
|Fresh tomato coulis:|
|Plum tomatoes||1 Pound, cored and quartered (6 nos, Roma)|
|Extra virgin olive oil||2 Tablespoon|
|For mashed potatoes with celery root and pear|
|Russet potatoes||1 Pound, peeled and cut in 1-inch dice|
|Celery root||1 Pound, peeled and cut in 1-inch dice|
|Pears||1 Pound, peeled and cut in 1-inch dice (preferably Bartlett or d'Anjou)|
|Milk||1⁄3 Cup (5.33 tbs)|
FOR THE PESTO, combine the mint, garlic, pine nuts, and Parmesan cheese in a food processor and blend until very smooth.
With the machine running, slowly pour in the olive oil.
Season to taste with salt and pepper.
Transfer the pesto to a bowl and stir in the chopped hazelnuts.
FOR THE TOMATO COULIS, puree the tomatoes in a food processor or blender.
Add the olive oil and continue processing until the coulis is thick and well mixed.
Pass the mixture through a strainer to remove seeds and bits of skin.
Season to taste with salt and pepper, put the coulis in a small saucepan, and gently warm over low heat.
FOR THE MASHED POTATOES, combine the potato and celery root in a large pan with just enough water to cover.
Bring to a boil, lower the heat, and simmer until the potatoes are nearly tender, 12 to 15 minutes.
Add the pears and simmer 5 minutes longer.
Meanwhile, heat the milk with the butter in a small saucepan just until the butter has melted.
Drain the potato mixture well and return it to the pan.
Add the warm milk mixture and mash.
(Do not thoroughly puree the mixture—a few lumps are desirable.) Season to taste with salt and pepper and cover the pan to keep warm.
PREHEAT THE OVEN to 375°F.
DRIZZLE THE STEELHEAD pieces with the oil and rub it thoroughly over the fish.
Heat a large, ovenproof skillet, preferably nonstick, over high heat.
Add the fish pieces, skin side up, and sear for 1 to 2 minutes.
(Don't disturb the fish for the first minute or it will stick.) Turn the fish and sear on the skin side for 1 to 2 minutes.
Spread about 1 tablespoon of the pesto over each piece of fish, then transfer the skillet to the oven.
Bake until the fish is nearly opaque, 7 to 10 minutes.
TO SERVE, spoon a generous dollop of mashed potatoes into the center of 6 individual plates.
Drizzle some of the warm tomato coulis around the potatoes and set a portion of fish over the potatoes.
Grind some pepper over the coulis and serve.