
The official vegetable of Georgia since 1990, the sweet, mild Vidalia onion is recognized worldwide for its gentle flavor. However, Vidalias can only be grown in a 20-county production area in and around Vidalia, Georgia, to legally wear the Vidalia label. Because of their thin, tender skins and relatively high sugar content, Vidalia onions are more perishable than most and need to be consumed within about one week of purchase. Look for Georgia-grown Vidalias at farmers markets around the Southeast in early spring through the summer.
Although a regular white sweet spring onion would make a fine substitute, Vidalia's signature sweetness is gorgeous with the saltiness of bacon and the mild, lemony bite of fresh thyme in this savory tart. Serve with a salad and you've got a meal to remember. If you want to bypass making tart pastry, go ahead and buy prepared pastry at the grocery.