Preheat the oven to 350 degrees. Put the celeriac and garlic in a large saucepan and cover with water. Simmer over high heat until the celeriac is tender, about 15 minutes. Drain the celeriac and garlic and place them on a baking sheet. Bake the celeriac and garlic for about 10 minutes to dry them. Remove from the oven, return to the saucepan, and mash well with a potato masher. Add the mascarpone and butter and mix thoroughly. Season to taste with salt and pepper and serve warm. Per serving: 84 Calories (kcal); 6g Total Fat; (61% calories from fat); 1g Protein; 7g Carbohydrate; 16mg Cholesterol; 79mg Sodium Food Exchanges: 0 Grain(Starch); 0 Lean Meat; 1 1/2 Vegetable; 0 Fruit; 1 Fat; 0 Other Carbohydrates Converted by MM_Buster v2.0n.