To have comforting, creamy, mashed potatoes without chalking up 35 grams of carbs in a one-cup serving, try this half and half strategy. Use half the amount of potatoes you want for your dish.
A medium potato contains about 33 grams of carbs and 3 grams of fiber per cup. Then use an equal amount of either turnips (about 8 grams of carbs and 3 grams of fiber per cup), rutabaga (about 15 grams of carbs and 3 grams of fiber per cup), cauliflower (about 3 grams of carbs and 2 grams of fiber per cup) or some combination of the three. Boil or microwave the potatoes and vegetables, and mash these up together. Add softened butter. Then, warm some cream or half-and-half in the microwave, and beat in until smooth. Salt and pepper to taste. For extra flavor, add minced garlic (raw or gently cooked) to the butter mixture, or mix in some grated Parmesan, romano, or asiago cheese.