Preheat the oven to 400 degrees
Toss the broccoli florets with olive oil, balsamic vinegar, garlic, basil, salt, and pepper. Spread evenly over a sheet pan.
Add tomatoes to the sheet pan.
Roast in the oven without stirring for about 20 minutes. The broccoli will be done when the edges are crispy, and the stems are tender. The tomatoes will blister.
Remove broccoli from the oven. Toss with fresh mozzarella cheese and serve.