In a large mixing bowl, combine grated onion, ground beef, breadcrumbs, salt, and pepper. Add heavy cream and egg, and mix gently. Let rest for 5 minutes.

Divide the mixture into four equal portions and shape each into a patty. Heat a skillet and sear the patties for 4-5 minutes on each side until golden brown.

In the same skillet, reduce heat and add garlic and any leftover onion. Sauté until fragrant. Sprinkle in salt, pepper, and flour, stirring to create a roux.

Gradually pour in chicken broth, scraping any browned bits. Allow to simmer.

Stir in heavy cream and dill, bringing to a gentle boil. Return the patties to the skillet and simmer for an additional 5-6 minutes.