Pat the fish dry with a paper towel. then lightly sprinkle both sides with salt and pepper.
Place two Lodge 8-inch cast iron skillets over high heat. Add I tablespoon of the oil and ½ tablespoon of the butter to each skillet. When the butter is melted. add 2 fillets, flesh side down, to each skillet, and cook over high heat for about 4 minutes. (Note: After 2 minutes, carefully slide a metal spatula under the fish to ensure it is not sticking.) Turn the fillets over {the fish should be nicely browned but not dark), and cook for another 2 to 3 minutes. Carefully remove the trout to warm serving plates. Remove one skillet from the heat.
Add the remaining 4 tablespoons butter to the other skillet, and melt over high heat. Add the almonds, and swirl the pan to coat them with the butter. Cook for a minute or so. Add the shallot, parsley. thyme. and salt and pepper (a nice pinch of each should do). Toss the almonds constantly over the heat until they become uniformly light brown. Turn off the heat, add the lemon juice, and toss. The mixture will sizzle and foam. Top each fillet with the almond mixture.