Put the vegetables into a large roasting tin, drizzle with half the oil and seaon to taste.
Roast for 20 mins turning once in a while until softened. Drizzle with the honey.
Scatter the torn ciabatta and sunflower seeds over the top and return to the oven for a further 5 mins or until toasted.
Put the spinach into a large bowl and tip in the vegetables and ciabatta. Whisk the vinegar, mustard and remaining oil together, season to taste and toss into the salad until the spinach wilts slightly.