You're gonna need:
For the trout
2 tout fillets
Dill weed (LOL)
A shallow baking dish.
For the potatoes
A bag of redskin potatoes
1 garlic clove
A cookie sheet
Make the potatoes first. They take the longest. Set your oven to good ole 350. Then get out your cutting board and start cutting up your washed red potatoes. Leave the skin on, cut them into chunks. Not too small, but smaller than a quarter of the spud, you dig? I didn't have a ruler handy, but I figure they were probably 1" x 1" or so.
When they're all chunked up nicely (we used to say that particularly long, unbroken paragraphs were "chunking up the page" in my critique group), put them in your mixing bowl Pour on the olive oil. Don't go crazy here, you just want to be able to coat the potatoes you've got, not drown them. Mince up that garlic clove. Throw it in there, too. Sprinkle on the rosemary, fresh or from the cupboard, I don't care, both work. Toss it like a salad, then spread the taters out on your cookie sheet. Throw them in the oven. You're a superstar.
Take your trout fillets and lay them skin side down. Take your handy dandy pliers and run your finger down the fillet, feeling for pin bones. If you find one, grab that fucker with the pliers and pull it out. Do it like an eyebrow hair, pull in the direction of the growth. Try not to rip a bunch of fish off, too, you know. Save some for the oven.
After that part is done, get yourself a sheet of aluminum foil that is big enough for both fillets. Slap them on there and pour some olive oil on the fish, the foil, go crazy. Olive oil is good for you. Then season it with dill and pepper. Throw another piece of foil over the top and seal the edges together. Then put the packet in a shallow baking dish and put it in the oven.
The potatoes are done when you can stick a fork through them easily. The fish is done when when the flesh is flakey when you rake a fork over it. I don't use timers when I cook, but I'd estimate 20 minutes. Check on it at 15, though.
You can either take the skin off the fish before you serve it or just let the eater do that his or herself. I, personally, like to take the skin off at my plate, because it feels like a primal celebration of the kill.
Serve some other veggies with that, too. Broccoli is always good.