Heat 2 tablespoons (30 ml / 1 fl oz) of olive oil in a large, heavy-bottomed skillet or Dutch oven over medium-high heat.
Add the quartered Brussels sprouts and sear, stirring occasionally, until they are browned and slightly crispy, about 3-5 minutes.
Transfer the sprouts to a plate and season with salt and pepper.
In the same skillet, reduce the heat to medium and add the remaining 1 tablespoon (15 ml / 0.5 fl oz) of olive oil.
Add the chopped onion and a pinch of salt, and sauté until softened and translucent, about 5-7 minutes.
Add the Arborio rice to the skillet and stir constantly for about 1 minute to toast the grains and coat them in oil.
Pour in the white wine to deglaze the pan, scraping up any browned bits from the bottom.
Cook until the wine has almost completely evaporated.
Begin adding the warm vegetable broth one ladleful (about 1/2 cup / 480 ml) at a time, stirring frequently. Wait until the liquid is almost fully absorbed before adding the next ladleful.
After about 10 minutes of this process, stir the seared Brussels sprouts back into the risotto.
Continue adding the broth, one ladleful at a time, stirring until the rice is al dente and creamy. This entire process should take about 20-25 minutes.
With the last ladleful of broth, stir in the cooked black rice and cook until the liquid is absorbed.
Remove the skillet from the heat.
Stir in the Parmesan cheese, lemon zest, lemon juice, and fresh parsley.
Season generously with salt and pepper to taste.
Serve immediately.
Don't rinse your Arborio rice! The starchy coating on the grains is essential for creating that classic, creamy risotto texture.
