Preheat the oven to 200 degrees top / bottom heat. After marinating you start with the potatoes, wash them and pat dry with kitchen paper. Then these are halved, quartered. Take a baking sheet, line it with parchment paper and place the quartered potato pieces on it.
Drizzle with the rapeseed oil to taste. Salt, pepper and top with the rosemary sprigs. Then you put the covered baking sheet in the preheated oven and let it cook for about 25 minutes. After cooking, take the baking sheet out of the oven and put the whole thing again.
Wash the small tomatoes once, pat dry and cut in half. Spread these on the baking sheet. Remove the frozen beans from the bag and distribute them over the ingredients that are already on the tray. Remove the marinated chicken breasts from the sauce and place on top.