Preheat your oven to 200°C/180°C(fan)/400°F/Gas 6. Line a large baking sheet with parchment paper.
Put all of the ingredients into a mixing bowl.
Mix everything together until well combined.
Using damp hands, roll the mixture into 15 meatballs.
Notes
If you want a smoother meatball mixture, blend the cottage cheese for a few seconds until mostly smooth. This step is optional, but it does hide it more if that's an issue for you.
Try not to overwork the cottage cheese meatball mixture because that can make the meatballs firm. The mixture should feel soft and slightly moist but still easy to shape. If it seems too wet, add another tablespoon or two of panko.
Use lightly damp hands when shaping the meatballs. It makes the mixture less sticky and helps create smoother balls.
Try to keep the meatballs a similar size so they cook evenly.
Do not overbake. Lean beef dries out faster than higher-fat mince, so check them a few minutes before the finished cooking time.