To make the sauce, start by making a roux. Melt the butter over medium heat. Add the flour and cook for 1 minute, stirring constantly. Add garlic and cook approximately 30 seconds. Whisk in the milk and beer. Cook until thickened slightly, approximately 3-5 minutes.

Remove from heat and stir in the freshly grated cheese and sour cream for the sauce. Season with salt and pepper to taste.

To make the filling for the egg rolls, in a large bowl, stir together mashed potatoes, sour cream, shredded cheddar cheese, garlic powder, chives, and bacon until well combined. Season with salt and pepper to taste.

In a small bowl, whisk together water and cornstarch for the egg rolls. Set aside.

To wrap your egg rolls, start with a clean, flat surface. Lay one wrapper so one of the corners is facing you (like a diamond). Dip your fingers in the cornstarch water and spread on each edge of the egg roll wrapper.

In the corner closest to you, spoon 1 1/2 to 2 tablespoons of the mashed potato filling into the center. Lift the bottom corner up and begin to roll away from you, making sure you tuck the corner under as you roll. Once you are halfway up the wrapper, fold in the left side and then the right side towards the center.

Continue rolling away from you until only the final corner is ready to roll. Dip your fingers in the cornstarch and water mixture you made earlier and brush it over the final corner. Finish the roll, brush a little more of the cornstarch mixture along the seam, and place seam-side down. Make sure you roll the egg rolls tightly. If they are too loose, they will fall apart when you fry them.

To fry the egg rolls, fill a pot with 4-5 inches of cooking oil. Heat the oil to 350 degrees. Gently add the egg rolls to the hot oil, frying no more than 3 or 4 at a time, turning occasionally. Fry until the egg rolls are golden brown on all sides, approximately 2 minutes. Place on paper towels to drain and cool.

Serve immediately with beer cheddar dipping sauce.