The Creamiest Sous Vide Mashed Potatoes - A Duck's Oven

Ingredients

• .8 lb russet potatoes (about 1 large) (peeled & cut into 1 inch cubes)
• 1.6 lbs yellow potatoes (about 4 large) (peeled & cut into 1 inch cubes)
• 1/2 cup salted butter (sliced into pats)
• 1 1/2 tsp kosher salt
• 1 tsp Italian seasoning
• 1 1/2 tsp garlic powder ((sub with 4 cloves minced garlic if desired))
• 1/2 tsp freshly cracked black pepper
• 1/2 cup milk (1%, 2%, or whole)
• 1/3 cup heavy cream
• 1/4 cup sour cream