Heat the vegetable broth in a saucepan over low heat and keep it warm throughout cooking.
In a large, wide pan, heat the olive oil over medium heat. Add the diced onion and cook for 3–4 minutes until soft and translucent.
Add the minced garlic and cook for 30 seconds until fragrant.
Stir in the Arborio rice and toast for 1–2 minutes, stirring constantly, until the grains look slightly translucent around the edges.
(Optional) Pour in the white wine and stir until it has fully absorbed.
Add one ladle of warm broth to the rice, stirring gently until absorbed.
Continue adding broth one ladle at a time, allowing it to absorb before adding more, stirring regularly.
After about 15 minutes, stir in the peas and continue cooking.
Once the rice is creamy and al dente (about 18–20 minutes total), remove the pan from heat.
Stir in the butter, Parmesan cheese, and chopped mint.
Season with salt and black pepper to taste.
Let the risotto rest for 1–2 minutes before serving. Add lemon zest if desired and serve immediately.