Heat broth in a saucepan over low heat. Keep it warm but not boiling.
Sauté diced sweet potatoes in a little olive oil until tender, or roast at 400°F (200°C) for 20–25 minutes for deeper flavor. Set aside.
In a large pan, heat olive oil or butter over medium heat. Cook onion until soft and translucent. Add garlic and cook for 30 seconds.
Add Arborio rice and stir for 1–2 minutes until edges appear slightly translucent.
Pour in white wine and cook until mostly absorbed
Add one ladle of warm broth. Stir gently until absorbed. Continue adding broth gradually, stirring occasionally.
When rice is nearly tender, stir in cooked sweet potatoes.
Turn off heat. Stir in Parmesan cheese. Season with salt and pepper. The risotto should be creamy and slightly loose.
Let rest for 5 minutes before serving. Serve warm.
