selective blur on a studio shot of a three bulbs of red onions on a black background. red onion, also called purple or

red onion purple blue three onions isolated black background single food vegetable bulb allium cepa herbs nutrition grocery cuisine culinary plant agriculture raw organic golden ingredient closeup studio shot root seasoning vegetarian macro scallion healthy natural nature selective blur bulbs background called mainland european countries cultivars purplish-red skin white flesh tinged red commonly used cooking dye