Drain tuna cans completely. Remove excess water.
Flake tuna into small pieces using fork.
Add cottage cheese to mixing bowl.
Combine tuna with cottage cheese gently.
Dice red onion into small pieces.
Chop celery stalks into bite-sized pieces.
Cut cucumber into small cubes.
Add all vegetables to tuna mixture.
Sprinkle fresh dill over the mixture.
Squeeze lemon juice over everything.
Season with salt and pepper.
Mix all ingredients until well combined.
Taste and adjust seasoning as needed.
Chill for 15 minutes before serving.