Heat 1 tbsp of oil and fry the onion and mushrooms until most of the liquid has evaporated and they have nicely browned.
Add the Worcestershire sauce, paprika and garlic and cook for a further minute. Remove from the heat and allow to cool.
In a large bowl, add the breadcrumbs, oats, salt, pepper, oregano and cheddar cheese, stirring just until everything is combined.
Beat the egg and then pour into the dry ingredients along with the mushroom and onion mixture. Stir until well combined.
With your hands, scoop the mixture into three balls. Press together so that the mixture sticks together and place on a tray lined with baking paper. Gently shape the mixture into rounds and flatten slightly.
Place in the fridge for at least three hours.
When ready, heat 1 tbsp oil and gently fry the patties for a couple of minutes on either side.
Serve in a soft burger bun with mayo, lettuce and tomatoes. Enjoy!
Notes
I have converted grams to cups/ounces/tablespoons using online converters. Although I have no reason to believe they are inaccurate, please be aware that I have not made this recipe using imperial measurements.