Sticky date and sausage traybake

Name: Sticky date and sausage traybake
Prep time: 10 min
Cook time: 1 h
Total time: 1 h 10 min
Cuisine: Mediterranean
Ingredients: 400g baby potatoes , halved or quartered if large; 200g brussels sprouts , halved; 1 red onion , peeled and cut into 8 wedges; 150g Medjool dates , pitted and torn in half; 8 good-quality sausages; 5g oregano; 3 thyme sprigs; 65ml olive oil; 2 tbsp red wine vinegar; 2 tbsp maple syrup; 1 tbsp wholegrain mustard; 2 garlic cloves , grated; ½ tsp ground cinnamon; 1 tsp nigella seeds; 1 tsp ground cumin; 10g parsley , roughly chopped