Put one tablespoon of the flour into a small bowl. Add the buttermilk, eggs, pepper, salt, garlic powder, onion powder, and paprika. Mix together until smooth, and set aside.
In another small bowl or plate add the remaining flour and cornmeal, mix together.
Slice the tomatoes into 1/4 inch slices. Cut a notch out of the stem portion.
Add enough oil to a large pan, skillet, or cast iron pan, 1/4 - 1/2 inch up the side of the skillet.
Heat the oil over medium heat to 350°F. Use an oil or candy thermometer if you aren't used to frying foods.
Dredge tomato slices into the seasoned buttermilk mixture, thoroughly coating the slice.
Then coat it in the flour/cornmeal mixture, letting the excess flour mixture fall off.
Place the tomato into the hot oil and fry for about two minutes per side or to your desired color.
Take the fried tomatoes out of the skillet and place them on a paper-towel-lined plate to soak up the excess oil. Place the cooked tomatoes on a wire rack so the tomatoes don't get soggy on the bottom. Repeat with the remaining ingredients.
Serve immediately with your favorite ranch for dipping.
If you don't have buttermilk, you can make your own by adding 1 tablespoon of white vinegar for every cup of needed buttermilk to milk. In the measuring cup, add the vinegar and then fill to the one cup line with milk. Let it sit for 5 minutes and you'll have buttermilk.
Freeze before cooking - After coating your tomatoes, place them individually on a plate in the freezer for 30 minutes. Then transfer them to an airtight container or zip-seal bag. When ready to cook them, simply take them from the freezer to the hot oil, thawing isn't necessary. Additionally, you can slice and freeze green tomatoes as well without coating.
Reheating - To be perfectly honest, they don't hold up well to reheating. Fried green tomatoes generally should be eaten immediately otherwise they get soggy, but if you do want to reheat them, place them on a baking sheet with wire rack in a 350°F oven for a few minutes. Additionally, you could do a quick refry.
Other seasonings - Cayenne pepper, chipotle pepper, smoked and/or hot paprika instead of sweet, cajun seasoning blend, or creole seasoning blend. Add your favorite dried herbs to dry mixture. Or even some parmesan cheese and Italian seasoning blend.