When the tomatoes are ready, place a large skillet over medium-high heat with 2 turns of the pan of EVOO, about 2 tablespoons. While the pan heats up, combine the ground sirloin, Balsamic Drizzle, Worcestershire, parsley and some salt and pepper in a large mixing bowl. Combine the ingredients and shape the mixture into four patties. Drop the burgers into the hot pan and cook until seared and cooked through, about 5 minutes per side. When you flip the burgers, lay a slice of provolone over each patty to melt.
While the burgers are cooking, set up a food processor. In the bowl, combine the watercress, walnuts, lemon juice, chopped garlic and some salt and pepper. Pulse the machine a few times to chop everything up and then turn on the machine and stream in the remaining 1/4 cup EVOO until it forms a smooth pesto.
When everything is almost ready, place the bread slices on a baking sheet and pop them under the broiler until toasted. When they come out of the broiler, rub the toasted side with the whole clove of garlic and give them a drizzle of EVOO and a sprinkle of salt and pepper.
To assemble, layer the burgers with a couple slices of roasted tomato and a good dollop of pesto between two slices of toasted bread.