Melt the butter and olive oil in a large stockpot over medium heat. Add the onion and cook until translucent ( around 5 minutes ).
Add the celery, carrot, and mushrooms and cook for 3 more minutes.
Stir the ground beef into the vegetables and cook until the meat crumbles and is cooked through. This should take around 6 minutes.
Add 1/4 teaspoon salt, black pepper, cayenne pepper, and the nutmeg to the meat mixture.
Pour the milk into the pan, and stir to combine. Bring to a simmer, stirring often, until the milk has reduced down to a saucy coating for the meat ( there will still be a small amount of liquid in the bottom of the pan ). This will take anywhere from 10 to 15 minutes.
Crank the heat up to medium high, and stir in the white wine. Keep stirring until the wine reduces down like the milk did ( this will take about 20 minutes ). There should just be a thickened sauce at the bottom of the pan/meat mixture now.
Stir in the crushed tomatoes and the water, reduce the heat to low, making sure the sauce stays at a simmer. Simmer the sauce for at least 4 hours, stirring occasionally. Feel free to add more water if the sauce starts to cake to the pan. I usually have to add around a half cup of water for each hour of simmering.
Serve over wide-cut ribbons of fresh homemade pasta, and top with a sprinkle of pecorino romano cheese.