Turn pressure cooker on sauté. Add 4 tablespoons butter and allow to melt.
Hit cancel on pressure cooker and whisk in flour.
Slowly whisk in beef broth.
Whisk in milk.
Stir in 1 teaspoon salt and 1/2 teaspoon black pepper.
Remove from pressure cooker and set aside.
Add water and potatoes to pressure cooker.
Hit manual button on pressure cooker and set for 10 minutes. Close lid. Make sure valve is set to seal position. (will take almost 10 minutes to come to pressure)
When timer is done turn valve to quick release. (Watch out for hot steam)
Open pressure cooker and add 2 tablespoons butter.
Mash together.
Stir in nutmeg, 2 teaspoons salt and 1/2 teaspoon black pepper.
Pour in 1/2 cup warm milk and continue to mash until potatoes are creamy.
Serve with warm gravy and ENJOY!
Notes
To reheat the gravy: place in microwave for 1 minute. If gravy is too thick, stir in 1 tablespoon milk, until it reaches the consistency that you prefer.