Preheat the oven to 350 degrees F. Line two baking sheets with parchment paper (or tinfoil) and spray with cooking spray.
Heat olive oil in a saute pan over medium heat. Add onion and cook 5 minutes, stirring frequently. Add cauliflower and saute another 10 minutes until most of the moisture is absorbed and cauliflower , peas and onions are lightly browned. Add garlic and saute one more minute. Remove pan from heat and let cool slightly.
In a large mixing bowl, combine beef, cheese, chips, milk, pepper, salt, garlic powder, parsley and egg with your hands. Add in cooled cauliflower & peas and mix to combine.
Scoop mixture into your hands by heaping tablespoon and roll into balls.
Coat the ball into oats mixture & fry it till golden brown. Serve with sauce.