Onion grating - Place breadcrumbs in a bowl. Use a box grater and grate the onion over the breadcrumbs. Mix with fingers, leave to soak for a few minutes.

Mix - Add remaining Salisbury Steak ingredients into the large bowl. Use your hands to mix until just combined. Mix well for a couple of minutes until the mixture becomes a bit "pasty" which will ensure your patties hold together well.

Form patties - Divide into 5 and pat very firmly into oval patties around 3/4" / 1 2/3 cm thick.

Brown patties - Heat oil in a skillet over high heat. Add the steaks and cook the first side for 1 minute or until browned, then gently flip and brown the other side (they will still be raw inside). Remove onto plate.

Cook aromatics - If skillet is looking dry, add a touch more oil. Add chopped onion and garlic and cook for 2 minute until onions are a bit translucent.

Cook mushrooms - Add the mushrooms into the skillet and cook for 2 - 3 minutes until golden.

Make gravy roux - Turn heat down to medium. Add butter. Once melted, add flour and cook for 30 seconds, stirring constantly.

Gravy - Gradually add in beef broth, stirring as you go. Once mostly lump free, whisk in remaining Gravy ingredients.

Finish cooking steaks - Add steaks along with the juices on the plate. Cook for 5 - 7 minutes, or until gravy is thickened, stirring occasionally around the steaks. If the gravy thickens too quickly, add more water.

Season gravy - Remove steaks onto a plate. Taste gravy and adjust salt and pepper to taste.

Serve salisbury steaks topped with the mushroom gravy - over mashed potato is ideal! Sprinkle with a bit of parsley if desired.