Add olive oil to a large nonstick skillet over medium heat. Cook the grated onion in the oil for about 5 minutes until it just begins to brown. Remove from heat and allow to cool slightly.
In a large bowl, combine the ground beef, ground pork, garlic powder, salt, pepper, Parmesan cheese, ricotta, egg, and cooked onions. Mix together until the ingredients are well combined.
Scoop the beef mixture into 1 ½” balls (about the size of a golf ball). It will make about 25 meatballs.
Heat a swirl of oil in the same non-stick skillet over medium heat. Add meatballs to the pan. You will need to leave space to turn the meatballs so will likely have to cook the meatballs in batches. Cook each batch of meatballs about 7 minutes, turning them frequently to brown all the sides evenly.
Use a spoon to scoop the meatballs out of the pan onto a plate and cover them with foil until you’re ready to serve.