Toss broccoli florets with 2 tbsp olive oil, salt, and pepper, then spread on a sheet pan and roast at 425°F for 10 minutes.
Rub pork tenderloin with 2 tbsp olive oil, minced garlic, chopped rosemary, zest of 1 lemon, salt, and pepper.
Push broccoli to the sides of the pan, add pork in the center, and roast for 12 minutes until internal temperature reaches 145°F.
Slice pork, squeeze fresh lemon juice over everything, and serve.