Crispy Oven Roasted Blue Potatoes

1 lb blue/purple potatoes unpeeled and cut into wedges 2 1/2 tbsp olive oil 1 1/2 tsp sea salt 1 tsp sugar 2 tsp smoked sweet paprika 1/2 tsp black pepper 1/2 tsp ground garlic 1/2 tsp coriander 2 tbsp potato starch or cornstarch optional…