Possible Clues:

• Edible root, eaten raw with salad
• Root crop recipe's one thing to eat
• The root of this is that Diana is in more than one spot
• Root with red skin
• 3 down
• Vegetable's beauty set down by artist
• Artist gets bowl for plant
• Vegetable mixed inside 72-Across
• Ingredient of salads I'd served up in quick succession
• Salad garnish