Start by bringing a large pot of salted water to a boil. Add the cauliflower florets and cook until they are very tender, about 7-10 minutes. Drain well to remove as much moisture as possible to ensure a creamy mash.

While the cauliflower is cooking, heat a skillet over medium heat. Add the butter and allow it to melt and start to foam. Once the foaming subsides, add the sage leaves. Cook until the butter has turned a golden brown color and the sage leaves are crispy, about 3-5 minutes. Remove the sage leaves and set them aside for garnish.

Transfer the drained cauliflower to a food processor. Add the browned butter, leaving behind the sage, and minced garlic. Process until smooth. For those who prefer a chunkier texture, you can use a potato masher instead of a food processor.

Pour in the heavy cream and continue to process until the mixture is velvety and resembles traditional mashed potatoes. Season with salt and pepper to taste.

Spoon the cauliflower mash into a serving bowl. Garnish with crispy sage leaves and optional grated Parmesan cheese. Serve warm as a delicious keto-friendly side to your favorite main course.