Preheat your oven to 415 degrees Fahrenheit. Line a large baking sheet and spray it with nonstick cooking spray.
Cut the broccoli into bite-sized florets. Place the broccoli onto the prepared baking sheet and toss the broccoli with 2 tablespoons of avocado oil. Arrange the broccoli in a single layer, without crowding, and season with salt and pepper. Use 2 sheet pans if necessary.
Place the broccoli onto the center rack of your preheated oven and roast at 415 degrees Fahrenheit for 10 - 12 minutes. While the broccoli is in the oven, add the lemon juice, garlic, and 1 tablespoon of oil to a small bowl and stir to combine.
After the broccoli has baked for 10 - 12 minutes, carefully remove from the oven and drizzle with the lemon garlic oil, then stir or toss to combine.
Place the broccoli back in the oven and bake for an additional 10 to 12 minutes, or until the broccoli is browned to your liking.
Remove from the oven, sprinkle with the parmesan cheese and toss to combine. Serve immediately and enjoy!