Wash and dry the tomatoes. Cut off the top 1/4 inch of the shoulders (including the stem portion) and bottom tip of the tomato and discard. Then slice into 1/4 inch slices. Put aside until needed.
Line a cookie sheet or shallow baking pan with paper towels and put into oven on very low/keep warm.
Place 1/2 c flour on paper plate or in shallow dish for first coating step.
In a shallow bowl, mix the eggs, buttermilk, hot sauce and water.
In another shallow container, mix the flour, cornmeal, panko, parmesan and seasonings.
Set up your dipping/frying station close to the stove with plain flour first, then egg dip, then crumb coating.
In a large skillet, heat about 2 to 3 teaspoons of butter and enough oil to cover the bottom of the pan to medium or medium high.
Dip several tomato slices in flour and shake off any exceess. Then dip in egg, then in crumb coating to cover. Press crumbs to surface to make them stick.
Place the dipped and coated slices in the pan and let cook until golden brown on the first side. If they get brown too quickly, lower the heat to medium and turn the slices over. Continue to cook until the tomato is slightly tender and the coating is browned. Remove from pan and place on paper towel lined baking pan in the oven to keep warm.
Repeat frying slices adding butter and oil as needed to fry each batch. Placing each batch on the pan in the oven as they are done.
Serve hot as a side dish or just by themselves.
Note: With 5 medium tomatoes, you should get approximately 4 to 5 slices per tomato or about 20-25 slices. Depending on how many each person will eat, adjust the amount to suit your needs. Also, the egg and crumb mixture should be more than enough for the amount listed. If you are frying a LOT of tomato slices, I would make 1 1/2 times or double the egg and crumb recipes.