In a medium bowl, combine ground beef, breadcrumbs, egg, garlic powder, dried onion, salt, and black pepper, mixing gently until just combined. Divide the mixture into four equal portions and shape each into a ball, then flatten them slightly into patties about ¾ inch thick.

Heat a skillet over medium heat and add a drizzle of olive oil along with a pat of unsalted butter. Once the butter is melted and foamy, carefully place the patties in the skillet. Sear the patties for about 5 minutes on each side until they turn a beautiful golden brown and reach an internal temperature of 160°F.

Remove the cooked hamburger steaks from the skillet and set aside. In the same skillet, add minced garlic and diced yellow onion, sautéing for about 2 minutes until fragrant and the onion is translucent. Season with a pinch of salt and pepper, then sprinkle in the Italian seasoning and add the tomato paste, stirring well to combine everything.

Pour in the heavy cream and toss in the fresh spinach, stirring until the spinach wilts down—about 2-3 minutes. Mix in the sun-dried tomatoes and grated Parmesan cheese, allowing the flavors to meld together.

Return the seared hamburger steaks to the skillet, gently nestling them into the creamy sauce. Let everything simmer for an additional 5 minutes, allowing the patties to absorb the rich flavors.