Peel and rinse your potatoes.
Cut potatoes into slices or chunks and place them in a large cooking pot. Almost cover with water, and place the lid on.
3 lb. russet or gold potatoes
Bring to a boil over high heat. Reduce temperature to medium and cook for about 20 minutes, or until fork tender. You'll want them nice and soft so they are easier to mash without leaving lumps.
Meanwhile, as you're waiting for your potatoes to cook, you can prepare the brown butter. Place 3 Tbs. salted butter into a saucepan or small skillet. Melt over medium/low heat, and continue cooking until it smells nutty and looks slightly browned. It may continue browning a bit more after removing it from the heat, so keep your eye on it. You don't want it burned.
7 - 8 tbsp. salted butter, divided
Drain the water from the potatoes. Mash with a hand masher or electric mixer until no more chunks remain.
Add the remaining 4 - 5 Tbs. butter, salt, pepper, and parsley flakes. Mix.
1 1/4 tsp. salt, 1/2 tsp. black pepper, 1/2 - 1 tsp. parsley flakes, optional
Slowly add milk (a little at a time), continuing to mix, and scraping the sides and bottom to make sure it's all incorporated. You may not need all the milk, just add till it's the right consistency for you. And you can substitute some heavy cream for milk if you like it more creamy.
3/4 to 1 c. whole milk
Mix until the potatoes are nice and creamy, and serve topped with brown butter.
Refrigerate and reheat any leftovers, if they're too thick add a bit more milk.