This is something I came up with when I was in university. I found it delicious and was a fairly regular staple of my diet then. I don't cook it a lot now, because I'm trying to cut down on the amount of soft drinks I consume, for health reasons and such.
You want a frying pan with high sides or a wok for this one. I learned to do this and stir-fries using water instead of oil, even in coated pans. The trick is to add the water with the ingredients.
So heat up your pan until water drops sizzle on it.
Take defrosted sole and fry it for a bit with a little butter/margarine and lemon juice.
Add Dr. Pepper, enough so that the sole is covered. Reduce heat to a quater of full heat.
Let simmer, stirring every once in a while, until Dr. Pepper has almost disappeared.
Turn off stove, remove from heat, let sole cool a little, and then enjoy!
I usually eat this with rice and some microwaved frozen veggies.