Cook the pasta according to the instructions on the package—be careful not to overcook it. Then rinse it with cold water, drain, and transfer to a bowl.
Cut the grapes into halves or quarters, dice the smoked chicken breast, and finely chop the red onion. Add all these ingredients to the bowl with the pasta.
Rinse the red beans with water, then drain them together with the corn using a sieve. Add them to the rest of the ingredients.
Toast the sunflower seeds in a dry pan until lightly golden, then add them to the salad.
Finally, add the mayonnaise, chopped green part of the spring onion, and season with salt and pepper. Mix all the ingredients thoroughly. Enjoy!