Heat the butter or oil in a large skillet over medium-high heat. Add the veal or beef cubes and cook until browned on all sides, about 5-7 minutes. Remove the meat from the skillet and set aside.
In the same skillet, add the chopped onion and cook until translucent, about 3-4 minutes. Add the minced garlic and cook for another 1 minute.
Pour in the beef or vegetable broth, scraping up any browned bits from the bottom of the pan. Allow the liquid to simmer for about 2 minutes.
Stir in the heavy cream and Dijon mustard. If you prefer a thicker sauce, mix the flour with a small amount of water to make a slurry and stir it into the sauce. Simmer for 3-5 minutes, or until the sauce has thickened to your liking.
Add the browned meat back into the skillet, stirring to coat it with the sauce. Cook for an additional 5-7 minutes, or until the meat is tender and the flavors are well combined.
Season with salt and pepper to taste. Garnish with chopped fresh parsley or chives.
Serve Hafalaab over rice, mashed potatoes, or with crusty bread.
Enjoy your meal!