Place the broccoli florets in a food processor and pulse until they reach the consistency of fine crumbs.
Transfer the broccoli to a small bowl and incorporate the lemon zest, lemon juice, microplaned garlic, chopped parsley, and 30ml of olive oil. Season with 2g of salt and 1g of pepper, then set aside at room temperature.
In a large mixing bowl, combine the ground beef, egg, panko, and Worcestershire sauce. Season with the remaining salt and pepper.
Divide the mixture into 4 equal portions and form into patties approximately 2.5cm thick.
Heat the remaining 15ml of olive oil in a stainless steel or cast iron skillet over medium-high heat.
Sear the patties for 4-5 minutes per side until an internal temperature of 71°C (160°F) is achieved and a Maillard crust has formed.
Remove the patties from the skillet and allow them to rest for 3 minutes.
Serve each patty topped with a generous layer of the broccoli gremolata.