4 trout fillets, about 4 ounces each, pin bones removed
2 ounces mesclun
Preheat the oven to 425°. Arrange the fennel wedges and 5 of the garlic cloves on a 12-inch sheet of foil and drizzle with 1 tablespoon of the canola oil. Fold the foil into a packet and roast for about 45 minutes, until the packet is sizzling and the fennel and garlic are tender. Transfer the fennel and garlic to a food processor and puree until smooth; season with salt and pepper.
Meanwhile, in a microwave-safe container, combine the dried porcini with the boiling water. Microwave on high power for 2 minutes, until the porcini are plumped. In a medium skillet, heat 1 tablespoon of the oil. Add the pine nuts and the remaining 1 clove of garlic and cook over moderate heat until the nuts are golden, about 3 minutes. Remove from the heat and strain the porcini liquid into the skillet, stopping before you reach the grit at the bottom. (Reserve the porcini for another use.) Add the balsamic vinegar and simmer over moderate heat until the liquid is reduced to 2 tablespoons, about 5 minutes; discard the garlic. Add 2 tablespoons of the oil and season the dressing with salt and pepper.
Heat the remaining 2 teaspoons of oil in a large nonstick skillet. Season the trout fillets with salt and pepper. Add one fillet at a time to the skillet, skin side down; press with a spatula to flatten for 30 seconds. Repeat with the remaining fillets until the pan is full. Cook over moderately high heat until the trout is browned on the bottom and nearly cooked through, about 3 minutes. Flip the fish and cook for 30 seconds longer.
Spread the fennel puree on plates and top with the trout. Drizzle half of the dressing on top. Add the greens to the remaining dressing in the skillet and toss to coat. Mound the greens on the fish and serve.