In a large mixing bowl, combine ground beef, breadcrumbs, beaten egg, finely chopped onion, minced garlic, salt, and pepper. Mix until well incorporated and let rest for a few minutes.

Scoop out portions and form into bite-sized meatballs, about one inch in diameter. Place on a parchment-lined baking sheet.

Heat a large skillet over medium heat with a tablespoon of oil. Brown the meatballs for 4-5 minutes on each side, cooking a total of 8-10 minutes.

Remove browned meatballs and add beef broth to the skillet, whisking to combine with brown bits. Whisk in cream and let thicken for 3-5 minutes before returning meatballs to the skillet.

Nestle meatballs into the gravy and let simmer for 5-7 minutes to meld flavors.

Peel and chop potatoes, boil in salted water for 15-20 minutes until fork-tender. Drain, return to pot, and mash with butter and milk.

Serve meatballs over creamy mashed potatoes with gravy drizzled on top.