Start by peeling and chopping your potatoes into small chunks. Then boil until fork tender.
Next, make your roux by melting 3 tbsp of butter with 3 tbsp flour. Mix together then add in milk and heavy cream. Whisk until smooth and add in sour cream.
Follow with roasted garlic, salt, pepper and cheese. Stir to melt and combine.
Combine the sauce and potatoes and mix well. Add in one extra half cup of cheese. Line a baking dish with one tbsp butter, then melt the remaining two tbsp of butter with the panko breadcrumbs. Spoon over your mashed potatoes and oven bake for thirty minutes at 400F. Enjoy.