Melt butter with olive oil in a large saucepan over medium heat; cook onion, celery, and carrot with pinch of salt until onion turns translucent, about 5 minutes. Stir ground beef into vegetables and cook, stirring constantly until meat is crumbly and no longer pink, about 5 minutes. Season meat mixture with 1 1/2 teaspoon salt, black pepper, cayenne pepper, and nutmeg.
Pour milk into ground beef mixture and bring to a simmer. Cook, stirring often, until most of the milk has evaporated and bottom of pan is still slightly saucy, about 5 minutes.
Raise heat to medium high and pour white wine into ground beef mixture; cook and stir until white wine has mostly evaporated, about 5 more minutes.
Pour tomatoes with juice into a large mixing bowl and crush them with your fingers until they resemble a slightly chunky sauce. Pour tomatoes into sauce; fill can with 2 cups water and add to sauce. Bring to a simmer.
Reduce heat to low and simmer, stirring often, until mixture cooks down into a thick sauce, at least 3 hours but preferably 4 to 6 hours. Skim fat from top of sauce if desired. If sauce is too thick or too hot on the bottom, add a little more water. Taste and adjust seasonings before serving.