In a bowl, combine the plant-based meat, breadcrumbs, all purpose seasoning, tomato paste, dry mustard, vegan Worcestershire sauce and no beef bouillon paste/cube. Mix with hands until well combined. Form 6 oval patties then refrigerate for 30 minutes.
In a large nonstick skillet over medium-high heat, cook steaks until browned, approximately 2 to 3 minutes per side. Remove from skillet, set a side.
Add onion and garlic to skillet and sauté for 2 to 3 minutes. Add the mushrooms, sprinkle with a good pinch of salt and pepper and continue cook for another 3 minutes until golden.
Decrease heat to medium. Add vegan butter. Once melted, sprinkle flour over skillet and cook for 1 minute, stirring constantly.
Gradually Wisk in no beef broth and water, stirring continuously. Bring to a simmer then stir in Dijon mustard and vegan Worcestershire sauce.
Return steaks to skillet. Decrease heat to medium-low and cook for 5 to 6 minutes, until gravy is thickened.
Serve Salisbury steaks with mashed potatoes and smother with mushroom gravy.