1. Preheat oven to 450 degrees. Generously season cauliflower with salt and pepper, toss with enough olive oil to just coat, and arrange in a single layer on a baking sheet. Roast, turning occasionally, for 15 minutes or until browned evenly. Remove from heat and let cool.
2. Toss cauliflower with mushrooms, dates, and walnuts. Add enough olive oil to coat, then add rosemary, parsley, and lemon juice. Season with salt and pepper.