Divide the chicken and season with plenty of salt. Melt the butter and caramelize the sugar in it. Then fry the chicken parts vigorously, after 10 minutes add chopped onion and garlic. Halve and mix in grapes. After a few minutes, deglaze with the two soy sauces and pour on the wine, drizzle a few squirts of lemon juice over the chicken. Fry in an oven preheated to 170 ° C for about 25 minutes.