Steaming trout would be a shame!
It's one of my favorite foods. I like to spread a thin film of good mustard on top the fillet to hold the crumbs and then coat the top with seasoned panko crumbs. I usually chop up some fresh herb of choice and mix with salt, pepper and the crumbs. Get some oil good and hot in your pan and then lay the fillets in with the topping side DOWN. Watch it carefully, and turn over when the pan releases them. When I turn them face up, I add a little lemon juice, dry vermouth or white wine to the pan (just a couple of tablespoons) and put a lid on the pan for about 4 -5 minutes. The wine and oil make a little sauce to pour over the fish after you plate it.
Catching 'em on spinners and spoons, cooking them every which way, eating them with fork or fingers, I love trout. Brookies are the best, steelhead is meaty, the closely related chars are moist and delicate.
Go ahead and cook them whole. The head, bones and fins will separate from the flesh like magic, and your dinner guests will be impressed.
One of my favorite ways is same as ChefJune's, using the spiciest mustard in my frig and panko seasoned with celery leaves. I've also poached gigantic rainbow trout slowly in rice wine, tsuyu (soy and dashi), lots of ginger and scallion julienne, and other ingredients. And, it is heavenly good smoked.