Preheat your oven to 200°C/Fan 180°C/Gas 6. Peel the potato, beetroot and carrots. Trim the courgette. Coarsely grate all of the veg into a large bowl (or see our tip at the end – and remember beetroot can stain, so if grating by hand, gloves will keep your fingers stain free). Peel and thinly slice the red onion. Trim and rinse the leek, then thinly slice it. Add to the bowl with the rest of the veg.

Zest the lemon. Add the zest to the pot of crème fraîche. Squeeze in the juice from 1/2 the lemon. Peel and crush the garlic and add it, along with the thyme leaves and plenty of salt and pepper. Mix well. Stir the crème mixture through the veg.

Grate the cheddar. Add two-thirds of it to the veg. Tip the creamy veg into a medium-sized ovenproof dish and cover with foil. Slide into the oven to bake for 20 mins till the veg start to soften. Remove the foil and cook for a further 20 mins till nicely browned on top.

After the gratin has cooked for 40 mins, scatter the remaining cheese over the top, then slide back into the oven for 10 mins, till melted.

Squeeze the remaining lemon into a small bowl. Whisk in 1 tsp Dijon mustard, ½ tbsp olive oil and some salt and pepper. Halve the cherry tomatoes and pop them into a large bowl with the salad leaves. Top with the mixed seeds, pour over the dressing and toss to coat. Serve the cheesy veg gratin with the salad on the side.