Cook pasta: Bring a large pot of water to a boil, add salt generously, and cook the pasta according to the package's instructions. Drain.
Chicken: While the pasta cooks, cut the chicken into small cubes. Heat the oil in a large pan and cook the chicken cubes, often stirring, until golden on all sides. Depending on their size, it should take 4-5 minutes.
Onions: In the meantime, slice the green onions. Add them to the pan and cook for two more minutes, stirring occasionally.
Check that the chicken pieces are cooked through, cut one in the middle, the meat should be white, not pink.
Add single cream, cube or crumble the cheese over the ingredients in the pan and stir to combine. Stir gently on very low heat for about 2 minutes until the cheese melts and the mixture thickens slightly.
Add most of the chives and freshly ground black pepper, stir.
Combine with the drained pasta. Do that either directly in the pan (if the pan is large enough) or in the pot you’ve just used for cooking the pasta.
Adjust the taste with salt and pepper.
Sprinkle with the remaining chives before serving.