In a medium-sized pot, heat the vegetable broth. Keep the broth hot during the cooking.

Cook the broccoli in a large saucepan with olive oil for about 10 minutes on medium-high heat, you can cook them in the broth if you prefer.

In the same pan where you cook the broccoli, heat the olive oil, add the chopped onion, and sauté until translucent.

Add the rice to the pan and stir well, toast the rice for 4 minutes.

Begin adding the warm vegetable broth to the rice, one ladle at a time. Stir continuously until the liquid is absorbed before adding the next ladle. Repeat this process until the rice is cooked al dente, which usually takes about 20 minutes. Add the cooked broccoli halfway through cooking, 

Once the rice is cooked, add grated Parmesan cheese and butter to the pan. Stir well to combine all the ingredients and allow the cheese to melt. 

Season with salt and pepper to taste.

Serve the broccoli risotto hot and garnish with some additional grated Parmesan cheese.