Prepare the dressing: In a small bowl, whisk together all dressing : buttermilk, mayonnaise, minced garlic, dry mustard, and cracked black pepper.
Set aside.
Set up your breading station: Place the flour in a shallow dish.
In a second dish, whisk the eggs and water.
Place the cornmeal in a third dish.
Season and coat the tomatoes: Sprinkle the tomato slices with salt and pepper. Dredge each slice first in flour, shaking off excess, then dip in the egg mixture, and finally coat thoroughly with cornmeal.
Fry the tomatoes: Heat the oil in a large skillet over medium-high heat.
Working in batches, cook the tomato slices for about 4 minutes total, flipping once, until golden brown and crisp.
Transfer to a paper towel-lined plate to drain.
Assemble the salad: On a large platter, arrange the salad greens.
Top with the warm fried green tomatoes, rinsed black-eyed peas, sliced radishes, and toasted pecans.
Serve: Drizzle the salad with the prepared buttermilk dressing and serve immediately.
Don't skip toasting the pecans! It takes just a few minutes in a dry skillet and dramatically enhances their nutty flavor and crunch.