Heat a griddle pan over a medium-high heat. Tip the carrots, courgettes and broccoli into a large mixing bowl, lightly season and toss together with the rapeseed oil. Once the griddle is hot, add the vegetables in batches and leave to slightly char for around 3-4 mins, then transfer back to the bowl. When all the veg is charred, add the remaining salad ingredients, toss together and set aside.
To make the saffron dressing, whisk the vinegar, mustard, saffron and sugar together in a bowl with a pinch of salt until the sugar has dissolved. Whisk in the oil gradually, then stir in the shallots. Dress the salad and serve.
