Instructions

1. Place the cauliflower and garlic in a medium saucepan, cover with cold water, and bring to a boil over high heat. Reduce the heat to medium to maintain a simmer, salt the water well, and cook for about 15 minutes or until the cauliflower is completely tender. Drain well.
2. To the bowl of a food processor add the cooked cauliflower and garlic, drained spinach, basil, lemon juice, lemon zest, and 1/4 cup olive oil. Puree until smooth and creamy, scraping down the sides as needed. Season with 3/4 teaspoon salt and pour the mixture into a large bowl.
3. Place a medium skillet over medium-high heat. Add 2 tablespoons olive oil to the skillet. When the oil is hot, add the mushrooms to the pan. Spread them evenly over the pan and allow to cook for 4 minutes on the first side, undisturbed, until golden brown. Stir with a wooden spoon, add the shallots, and continue cooking until both sides of the mushrooms are browned. Season with ¼ teaspoon salt and add the cooked mushrooms to the bowl with the creamy cauliflower.
4. Bring a large pot of salted water to a boil. Cook the rice pasta according to package directions. Drain well, reserving 1 cup of pasta water. Add the cooked pasta to the sauce with the mushrooms and toss well, adding pasta water as needed to loosen. Stir in the tomatoes, if using, and serve.