Mission American Kitchen occupies the old Aquavit space in the IDS Center, and it's a very likable, plain American restaurant that, if you can imagine such a thing, sort of splits the difference between a businessman's expense-account destination, a 1960s cocktail party, a soul-food shack, and a place your wife will find acceptable on your anniversary. For the ladies, Mission offers attractive lighting, a classy decorating scheme of cinnamon and terra cotta, a lovely wine list, and fresh oysters. For the expense-account crowd, Mission offers comfort foods tailored to the most crotchety elderly client (roasted chicken and scotch) or most rambunctious new hire (barbecued ribs and a beer). The dimensions of 1960s cocktail party can be uncovered once you set some creamy deviled eggs and house-made potato chips with sour cream next to your ice wine-enhanced martini. Mission accomplished.