Cook the croissants in the chicken broth until al dente, drain in a sieve and rinse with cold water.
For the sauce, sauté the onions in the butter, add the cream and Emmentaler, heat slowly while stirring, stir in the Schabziger, season to taste with nutmeg and pepper.
For the roasted onions, melt frying butter, add onions and roast over medium heat, stirring intermittently, season with pepper and sugar.
Add the Hörnli to the sauce and heat through. Stir in chives. Dressing. Sprinkle with onions.