In a large bowl, combine grated onion, ground beef, breadcrumbs, salt, black pepper, heavy cream, and egg. Mix gently by hand until just combined.

Divide the meat mixture into four equal portions, shaping them into patties approximately ¾ inch thick.

Heat a large skillet over medium heat and add olive oil and butter. Sear the patties for 4-5 minutes on each side.

In the same skillet, add minced garlic and onion. Sauté for about 2 minutes until translucent.

Sprinkle salt, pepper, and flour over the sautéed aromatics. Stir well and gradually pour in the chicken broth.

Once combined, pour in the heavy cream and add fresh dill; simmer until thickened.

Return the seared patties to the skillet and simmer for 5-6 minutes to heat through.

Serve warm, pouring the sauce over the patties. Pairs well with mashed potatoes or rice.