Preheat oven to 400°F. Trim the stem ends of the Brussels sprouts and pull off any yellow outer leaves. Halve each sprout lengthwise, then toss in a large bowl with olive oil, salt and pepper. Place on baking sheet and roast for 30 minutes until golden brown/turn, halfway thru cooking time.
Bring a large pot of salted water to a boil. Add cauliflower and cook until very tender, about 10 minutes. Reserve 1/4 cup of the cooking liquid and then drain well and transfer cauliflower to a food processor. Add 2 tablespoons olive oil and reserved water, 1 tablespoon at a time, and puree until smooth. (Or, mash cauliflower with a potato masher). Season with salt and pepper and serve.
Photos and recipes from Whole Foods. http://www.wholefoodsmarket.com/recipes/