With a sharp knife, cut kernels from corn cobs. Store kernels in fridge for now. In a large stockpot, bring corn cobs, water, and salt to a boil; lower heat to medium, cover, and cook 25 minutes. Use tongs to transfer cobs to a strainer; once cooled to the touch, use the back side of a knife to pop remaining soft corn out of the cobs into stockpot, then discard cobs. Add potatoes to stockpot and bring to a boil once more; lower heat to medium, cover, and cook 8 to 10 minutes, until potatoes are tender when pricked with a fork.
Meanwhile, melt butter in a skillet over medium heat and sauté carrot and onion until onion is soft and translucent. Add garlic, stirring another minute. When potatoes are cooked, transfer contents from skillet to the stockpot, then stir in corn from fridge, tomatoes, zucchini, bouillon, and pepper; continue cooking until heated through. Stir basil into chowder or sprinkle on top.
Per serving: 110 calories, 2 grams fat (1 gram saturated fat), 21 grams total carbohydrates, 4 milligrams cholesterol, 600 milligrams sodium, 3 grams fiber, 3 grams protein.
