Lay tomato slices in a colander over the sink and sprinkle liberally with salt. Let sit for about 30 minutes to allow water to pull out of the tomato. Gently wipe the tomatoes dry.
Mix the flour and Old Bay in a wide bowl or high-sided dish. Place buttermilk in another bowl.
Heat the oil over medium-high heat in a large cast-iron skillet or deep fryer.
Dip tomato slices in buttermilk then the flour mixture and place in oil. Be careful not to overcrowd the skillet. You will need to cook in at least a few batches depending on the size of your tomatoes. When the edges look brown, gently turn. Continue cooking until they are golden brown. Remove to a plate layered with paper towels to drain and continue with remaining batches.
Serves about 6.
Adapted from The Lady & Sons, Too (page 111) by Paula Deen.