Bring 6 cups low-sodium vegetable broth to a gentle simmer in a medium saucepan; reduce heat to low to keep warm.
Sauté & Toast
In a large skillet over medium heat, melt butter and olive oil. Add chopped onion and a pinch of salt; cook until translucent, about 5 minutes.
Stir in minced garlic and sliced mushrooms; cook until mushrooms release liquid and start to brown, about 8 minutes.
Add Arborio rice and toast, stirring until edges are translucent, about 2 minutes. Pour in white wine and simmer until absorbed, about 2 minutes.
Cook Risotto
Ladle warm broth, ½ cup at a time, stirring frequently and waiting until each addition is nearly absorbed before adding more. Continue until rice is tender with a slight bite, about 18–20 minutes.
Finish
Remove skillet from heat and stir in butter, Parmesan, and parsley. Season with salt and pepper. Let sit for 1 minute before serving.
Notes
Prep testing note: Uniformly slice mushrooms to reduce cooking time and ensure even browning.Storage testing note: Reheat leftover risotto gently over low heat with a splash of broth to revive creaminess without getting gummy.Food safety: Cool rice within 2 hours and store in an airtight container in the fridge for up to 3 days.