prairie moon is a long-time evanston, il., standby when it comes to casual, fun restaurants. but because it’s menu skews a bit cajun and barbeque, i haven’t been to eat there since my angioplasty two years go . my wife recently decided we should go there with friends for dinner, though, so i braced for maybe at most a salad. but i was pleasantly surprised that the chefs there were able to modify a menu offering and still keep it tasty and hearty. kudos to you, prairie moon. trout, potatoes andbroccoliat prairie moon, no salt and no crust but wonderful in taste and simplicity. looking at the menu, which includes both large and a small plate offerings, i was thinking fish would be the least salty, least fat-filled offering i could get. both salmon and trout are on the menu but each dish has no-nos for me. the salmon comes with mashed potatoes and butter. the trout comes with a pine-nut crust. i don’t eat nuts and usually crust means salt, either in cheese or some other way. so i asked