Griddles are available in either flat electric or slotted stovetop varieties and both are considered a fast and generally healthy option for cooking. A study published in the "Journal of Food Science" in 2009 found that compared to boiling, pressure-cooking, baking, microwaving and frying, griddling vegetables preserved the highest levels of antioxidants. Griddling gives vegetables a caramelized flavor similar to grilling but missing the smokiness. Many vegetables can be cooked on a griddle but the most frequently griddled vegetables are asparagus, corn, onions, eggplant, peppers and mushrooms.
Heat the griddle. While it's heating, cut the vegetables. Thinly slice large vegetables such as eggplant. Dice onions and peppers to ensure that they cook evenly. Asparagus can be left whole.
Brush olive or cooking oil directly on the vegetables. Do not pour it onto the griddle, which will cause the oil to collect and affect the flavor and texture of the vegetables.
Place the vegetables on the griddle. Allow the vegetables to caramelize. The side on the heat should begin to turn golden. Before flipping large vegetable slices, oil the uncooked side.