Preheat oven to 400 degrees.
Line bacon up on a rimmed baking sheet and bake until crisp, about 15 minutes. Remove the bacon and turn the oven on broil. Drain bacon on paper towels.
While the bacon cooks, bread the tomatoes. Add the egg and water to a shallow bowl. Whisk to combine. Add the bread crumbs, 1/2 tsp. salt, garlic powder, and dijon mustard to a plate. Whisk to combine. Add flour and 1/8 tsp. flour to another plate. Whisk to combine.
Dredge the tomatoes in flour, pat off excess. Dip in egg, let excess drip off. Dredge in flour. Place breaded tomatoes on a cookie cooling rack while you make the rest.
Add goat cheese, basil, chives, garlic, lemon and 1/8 tsp salt to a food processor. Turn the mixer on and process until goat cheese is whipped and herbs are minced. Season to taste with salt and pepper.
Spread butter on one side of sourdough. Place bread on a large baking sheet and pop under the broiler. Broil until toasted. Remove and season with salt and pepper.
Add 1 1/2 tablespoons olive oil to a large non-stick skillet. Heat to medium. Add half of tomatoes and cook until golden brown on both sides, about 2 minutes per side. Clean pan and add the remaining olive oil to the pan, repeat with remaining tomatoes.
To assemble: Spread goat cheese on the unbuttered side of every piece of bread. Add lettuce, two tomatoes, and 3-4 slices of bacon to half of the slices. Top with the other slice of bread. Cut in half and serve.