Potato Stroganoff

Heat the olive oil in a big oven-proof skillet. Add the chopped onion and garlic. Cook for 3-4 minutes over medium heat until they're softened.
1 tablespoon olive oil
1 medium onion
2 garlic cloves
Add the ground beef to the skillet and break it up as it cooks until it's nicely browned.
1 ½ lb ground beef
Sprinkle the flour over the beef and stir it through. Give it a minute to cook out.
2 tablespoons flour
Stir in your Dijon mustard and sour cream, and give it a good mix.
1 tablespoon Dijon mustard
1 cup sour cream
Slowly pour in the beef broth and simmer for 15 minutes until the sauce has thickened, but you still have enough liquid left to allow the potatoes to cook.
2 cups beef broth
While the sauce cooks, preheat your oven to 350 degrees Fahrenheit (180 degrees Celsius).
Layer the sliced potatoes on top of the sauce and pop the skillet into the pre-heated oven (middle rack) for 30 minutes or until the potatoes are fork-tender.
3 medium Russet potatoes
Sprinkle the mozzarella over the top, then bake for another 5 minutes on the top rack of the oven until the cheese is melty and golden.
½ cup mozzarella
Salt and ground black pepper to taste
Let it rest for 5 minutes before you dig in! This lets the sauce thicken up even more.