Ingredients:
1 medium head cauliflower, broken into small florets
½ cup salted butter
1 medium onion, diced
1 tablespoon red pepper flakes, or to taste
2 pints heavy cream
1 (16 ounce) package farfalle pasta
1 (14.5 ounce) can diced tomatoes
1 cup grated Parmesan cheese, or more to taste
Directions:
Place cauliflower into a large pot of salted water; bring to a boil. Reduce heat to medium-low and simmer until tender, about 10 minutes. Remove cauliflower with a strainer, reserving the cooking water in the pot.
Melt butter in a large skillet over medium-high heat. Add onion and cook until transparent, about 5 minutes. Add cauliflower florets and red pepper flakes; saute until browned, 7 to 10 minutes. Add heavy cream; cook until reduced by half, 10 to 15 minutes.
Meanwhile, bring the cauliflower cooking water back to a boil. Add farfalle and cook, stirring occasionally, until tender yet firm to the bite, about 12 minutes. Drain.
Add tomatoes to the cauliflower sauce; cook until heated through, about 1 minute. Add 1 cup Parmesan cheese to the cauliflower sauce; cook and stir until melted, about 1 minute more.
Combine pasta and sauce; toss until well coated. Sprinkle with additional Parmesan cheese to serve.