In a saucepan over medium-low heat, keep 4 cups of broth shimmering (not boiling).

Melt butter and olive oil in a heavy skillet over medium heat. Add chopped onion and cook until translucent, about 4 minutes, then stir in minced garlic for 1 additional minute.

Add Arborio rice and stir for 2 minutes, coating each grain until edges turn translucent.

Pour in dry white wine and simmer until almost fully absorbed, about 1–2 minutes.

Ladle in warm broth one scoop at a time, stirring frequently. Wait until liquid is mostly absorbed before each addition. Continue for about 18 minutes until rice is al dente and silky.

In a separate skillet, heat olive oil over medium-high heat. Add sliced mushrooms, season with salt and pepper, and cook 6–8 minutes until golden brown and crisp at the edges.

Remove from heat, drizzle mushrooms with truffle oil, and sprinkle fresh thyme or parsley. Toss gently.

Gently fold the truffled mushrooms into the risotto. Stir in Parmesan and a pat of butter until glossy. Season to taste, then plate piping hot.