Begin by bringing a large pot of salted water to a rolling boil over high heat. Carefully add the cauliflower florets, ensuring they are fully submerged. Boil for about 10 minutes or until the florets are fork-tender but not mushy. Once cooked, drain the water and let the cauliflower sit in the colander to release any excess moisture.

In the same pot, reduce the heat to medium and add the unsalted butter. Once it begins to melt, toss in minced garlic and sauté for 1-2 minutes until fragrant and lightly golden.

Transfer the drained cauliflower back into the pot, along with the sautéed garlic, sour cream, and grated Parmesan cheese. Using a food processor or a hand blender, blend the mixture until smooth and creamy, which should take about 2-3 minutes.

Once the cauliflower mixture reaches your desired smoothness, taste it and season with salt and pepper to your liking. Blend again briefly to incorporate the seasoning.

Spoon the creamy keto cauliflower mashed potatoes into a serving bowl and garnish with additional Parmesan cheese or fresh herbs if desired. Serve warm.