Tower of Power refers to:A. A Seventies funk bandB. A massive solar energy collector in the Australian outbackC. The floor-to-ceiling wine racks at Duo, currently housing more than 1300 vintagesD. Duo's stacked mozzarella and tomato salad, with olive and sun-dried tomato vinaigrette ($11)The answer is all of the above, but it's the food and wine at Duo that make the Brickell-area spot perfect for power lunching. No need to try to discreetly discover your clients' or colleagues' food preferences. The menu of creative but unfussy contemporary American fare covers all bases, from elegant (the Duo tartare — diced tuna plus thin-sliced salmon, with wasabi ponzu sauce, $14) to meat-and-potatoes (a churrasco with chimichurri rivaling that of any Argentine steakhouse, $19). For the price of the latter entrée, there's also a full three-course business lunch that changes daily. And light eaters are also accommodated with imaginative salads and sandwiches, or a protein diet-friendly broiled whitefish that's basic but perfectly done. Whatever one eats, there's a wine to match (at prices ranging from $25 to $1400), from a list eclectic enough to impress even the most jaded aficionado — and the place's knowledgeable but unstuffy servers will make you look good making the choice. It's possible to eat outside, at sidewalk café tables raised several steps above street level, but the high-ceilinged, sleek yet comfortably informal interior space is a more relaxing retreat from business hustle and bustle.