To prepare the trout almondine appetizers recipe, you'll need: 1 pound halibut fillets, 2 tablespoons olive oil, 1 teaspoon kosher salt, and 2 teaspoons thyme sprigs. Preheat the oven to 450?F (232?C) and grease a 13x9x2-inch baking dish with cooking spray. Set aside. In the bowl of an electric mixer fitted with the whisk attachment, beat the egg whites on medium-high speed until stiff peaks form. Gradually add the flour, beating after each addition until the mixture is stiff and glossy. Fold in the chopped parsley. Spoon the batter into the prepared dish and sprinkle with salt and pepper to taste. Bake for 12 to 15 minutes, or until golden brown. Serve warm or at room temperature.