Make the Hamburger Steaks
In a mixing bowl, combine the ground beef, chopped onion, minced garlic, almond flour or breadcrumbs, egg, Worcestershire sauce, salt, black pepper, and paprika.
Mix gently until just combined. Do not overmix.
Divide the mixture into 4 equal portions and shape into oval patties.
Cook the Patties
Heat 1 tablespoon olive oil in a large skillet over medium heat.
Add the hamburger steaks and cook for 4–5 minutes per side, or until nicely browned and mostly cooked through.
Remove the patties from the skillet and set aside on a plate.
Make the Garlic Mushroom Gravy
In the same skillet, add the butter.
Add the sliced mushrooms and cook for 5–6 minutes until softened and browned.
Stir in the minced garlic and cook for 30 seconds until fragrant.
Pour in the beef broth and Worcestershire sauce.
Add onion powder, black pepper, and salt. Stir well and bring to a gentle simmer.
To thicken, sprinkle in xanthan gum slowly while whisking, or stir in the cornstarch slurry.
If using, stir in the heavy cream for extra richness.
Finish the Dish
Return the hamburger steaks to the skillet.
Spoon the gravy over the patties and simmer for 5–7 minutes, until the steaks are fully cooked and the gravy is thickened.
Garnish with chopped parsley and serve hot.