Slice the tomatoes into ½-inch thick slices. Lightly season both sides with sea salt and freshly cracked pepper to taste.
Prepare the dredging station by placing ¼ cup of flour in a shallow bowl, and season with sea salt and freshly cracked pepper to taste.
In a separate shallow bowl, add the remaining flour, cornmeal, garlic powder, paprika, and cayenne pepper. Season with some sea salt and freshly cracked pepper to taste; mix well.
Lastly, whisk the egg and buttermilk in a bowl, season with sea salt and freshly cracked pepper to taste.
Heat enough oil to cover the bottom of a large skillet over medium-high heat until hot.
Meanwhile, dredge the tomato slices first by completely coating them in the flour. Next, dip them completely in the buttermilk mixture. Lastly, coat them in the cornmeal mixture.
Fry the tomatoes by using a fork, gently place the coated tomato slices in the HOT oil, and cook for 1-2 minutes, or until golden brown. Carefully flip the tomatoes and cook for another 1-2 minutes, or until golden brown. Side Note: Do not overcook the tomatoes, or they may become mushy inside.
Remove the tomatoes to a paper towel-lined plate, then season with a bit of sea salt to taste.
Serve by placing the fried green heirloom tomatoes on a serving plate. Sprinkle with fresh parsley and serve with the buttermilk ranch dressing. Enjoy!