For the roasted mushrooms

1. Preheat oven to 350°F (177°C). Grease or line a baking sheet with foil.
2. Spread sliced mushrooms on the baking sheet, spray with cooking spray, sprinkle with salt, and toss until evenly distributed.
3. Bake at 350°F (177°C) for 10-12 minutes, or until golden and slightly crispy.
4. Set aside.

For the risotto

1. Heat a large skillet over medium-high heat.
2. Add thinly diced onion and cook, stirring often, until translucent (3-4 minutes).
3. Add minced garlic and cook for 2 minutes, or until golden.
4. Process cauliflower florets in a food processor until it resembles rice (2-3 minutes).
5. Add cauliflower rice to the skillet and stir for 1 minute, until combined.
6. Heat vegetable broth to a gentle simmer.
7. Add ¼ cup of simmering broth to the skillet and cook, stirring constantly, until incorporated. Repeat until ½ cup of broth remains.
8. Stir in white wine vinegar to taste, then stir in the remaining broth.
9. Let the risotto sit on the stove over low heat to allow flavors to mingle and caramelize (optional).
10. Season with salt and pepper to taste.
11. Top with roasted mushrooms.