Zucchini is a very watery vegetable that will get soggy if cooked in any number of ways, but sometimes placing sliced zucchini on a paper towel to absorb liquid can help before sauteeing. You can also sprinkle the cut zucchini with salt and let them sweat for several minutes before cooking them. Or if you're cooking your zucchini in the oven, you can place the zucchini on a baking rack above a baking sheet so that the liquid drips off of the veggies without them having to soak as they cook.