Preparation

• Position a rack in the center of the oven and heat the oven to 450ºF.
• Arrange the trout skin side down on a foil-lined rimmed baking sheet. Sprinkle 2 tsp. salt and 1 tsp. pepper evenly over the trout. In a small saucepan, melt the butter and drizzle 4 Tbs. of it evenly over the fillets. Sprinkle the trout evenly with the parsley and the tarragon. Arrange 3 lemon slices over each fillet. Roast until the fillets flake easily when pricked with a fork, 10 to 12 minutes.
• Meanwhile, set the saucepan with the remaining melted butter over medium heat. Cook until lightly browned and fragrant, 3 to 5 minutes. Immediately remove from the heat and stir in the walnuts; keep warm.
• When the trout is done, use a large spatula to transfer the fillets to dinner plates—if the skin sticks to the foil, lift up only the flesh. Swirl the walnut butter around and then spoon it over the trout.

Serve with buttered baby red potatoes tossed with chopped fresh dill.