In a large pot add the cubed potatoes and cover with cold water. Lightly salt the water and bring to a boil.
In a small saucepan over low heat, melt the butter and add the milk and heavy cream. Keep the mixture warm until ready to fold into potatoes.
When the potatoes are fork tender remove them from the heat, drain them and run them through a potato ricer or food mill.
Remove the sauce pan from the heat and add it to the potatoes a little at a time. Gently fold in the dairy and repeat this process until all of the dairy has been added. Do not over work the potatoes to maintain a smooth consistency.
Add kosher salt to the potatoes and adjust seasoning to taste.
Brown Gravy
In a sauce pan over medium heat melt unsalted butter. Once butter is melted slowly whisk in the all purpose flour, adding it a little at a time to keep it from clumping. Keep whisking until all of the flour is incorporated. Cook roux for 3-4 minutes.
Once the roux is ready slowly add in the beef stock a little at a time. Let the Roux seize up before adding more stock. Keep repeating this process until all of the stock has been added to the roux. Whisk until the gravy is smooth with no lumps. Add in the Worcestershire sauce and whisk until well combined.
Turn the heat down to low and simmer the gravy until it reaches your desired consistency.
Once the gravy has reached your desired consistency, season the gravy with Kosher salt and freshly ground black pepper to taste.
Notes
Use the Right Potatoes: Russet potatoes are the best for mashed potatoes because of their high starch content, which gives them a fluffy texture when mashed. Avoid waxy potatoes, as they can lead to a gummy consistency.
Don’t Overwork the Potatoes: After mashing, avoid over-mixing, as it can turn the potatoes into a sticky paste. Gently fold in the butter, cream, and seasonings to keep them light and airy.
Warm Your Dairy: Always heat your milk and cream before adding it to the potatoes. Cold dairy can shock the potatoes, leading to a less smooth and fluffy result.
Salt the Water: Generously salt the water when boiling your potatoes. This step helps infuse flavor into the potatoes right from the start, making it easier to achieve perfectly seasoned mashed potatoes.
Use a Potato Ricer or Food Mill: For the smoothest, fluffiest texture, use a potato ricer or food mill instead of a masher. This method removes lumps and ensures a silky, airy consistency.