Preheat the oven to 200C/Gas 6/fan oven 180C. Pour the oil into a large roasting tin and heat in the oven for 3-4 minutes. Tip the sausages into the roasting tin and toss to lightly coat in the oil. Roast for 20-25 minutes or until browned and cooked through.
Drain the sausages well on kitchen paper, then tip them into a clean roasting tin. Blend the honey and mustard together in a small bowl, pour over the sausages and stir and shake them so they become coated. Return to the oven for 5 minutes, turning them over halfway. Serve hot or warm, with cocktail sticks and little pots of ketchup and mustard for dipping.
Prepare ahead: you can roast the sausages the day before, cool them on kitchen paper and then just keep them in a plastic container in the fridge overnight. Toss in the honey and mustard mix and reheat for 10-12 minutes in the oven before serving.
Stagger the cooking: heat half the sausages through in half the honey and mustard mix just before your guests arrive, then do the other half just as this first batch runs out.