Celery got its reputation as the ideal diet food from its low calorie content: A single cup of raw celery has just 16 calories. It is also cholesterol-free, contains only a trace amount of fat and has a high concentration of essential nutrients like vitamin K, vitamin A and fluoride. While celery is most often eaten raw or as an addition to soups, casseroles or stir fries, roasting celery at a high temperature can intensify the vegetable's flavor and caramelize its natural sugars, giving it a slightly sweet taste, say cookbook authors Laurie David and Kirstin Uhrenholdt. Use roasted celery as a side dish for meat, poultry or fish or as an ingredient in risotto or pasta.
Remove as many celery stalks from the whole vegetable's base as you plan to roast. Wash each thoroughly under cool, running water and pat dry with paper towels.
Trim off the end and leafy tops of each celery stalk with a sharp knife. Cut the trimmed celery into bite-sized chunks.
Line a rimmed baking sheet with aluminum foil or cooking parchment. Put the celery onto the baking sheet, drizzle the vegetables with olive oil and sprinkle them with salt and pepper, if desired. Use your hands to toss the celery until they are coated with the oil and seasonings.
Place the baking sheet into an oven preheated to 400 degrees Fahrenheit, suggests cooking expert Mollie Katzen. Allow the celery to roast, using tongs or a pancake turner to stir and turn the pieces every 10 minutes.
Roast the celery until the pieces are at your desired level of tenderness, typically between 15 and 30 minutes. Remove the baking sheet from the oven and serve the celery hot, cold or at room temperature.