For 2 minutes, sauté onions in two tablespoons of butter on medium-high heat. Cover pan, reduce to medium heat, and cook 5 to 7 minutes until translucent, stirring occasionally. Add garlic, alcohol, and cream and bring to a simmer. Reduce heat to low to low-medium and cook gently for 6 minutes. Remove from heat and stir in remainder of butter. Place raw livers in blender and add onion mixture with salt and pepper. Blend thoroughly and season to taste. Strain through a fine mesh strainer to remove any impurities. Fill an 8 oz. mason jar half way.