Double Cheese and Balsamic Onion Gratin

Meanwhile, halve, peel and thinly slice the red onion.

Heat a drizzle of oil in a large frying pan on medium-high heat. 

Once hot, add the onion and season with salt and pepper. Fry, stirring occasionally, until golden, 10-12 mins.

Remove from the heat, then add half the balsamic vinegar and the sugar for the onions (see pantry for amount). Cook until caramelised, 1-2 mins more.

Heat a drizzle of oil in the (now empty) pan used for the potatoes.

Once hot, add the garlic and mixed herbs. Cook until fragrant, 30 secs.

Add the creme fraiche, veg stock paste, reserved potato water and half the grated hard Italian style cheese. Stir to combine, bring to the boil, then remove from the heat. Season to taste with salt and pepper.

Lay half the cooked potato slices into an appropriately sized ovenproof dish. Top evenly with half the caramelised onion, then crumble over half the feta. Pour over the creamy dauphinoise sauce, then add a layer of the remaining cooked potato slices.

To finish, top with the remaining caramelised onion, feta and hard Italian style cheese.

Bake on the top shelf of your oven until golden brown and bubbling, 15-20 mins. TIP: Put the dish onto a baking tray to catch any drips.

In the meantime, quarter, core and thinly slice the apple (no need to peel).

In a large bowl, combine the remaining balsamic vinegar with the sugar and olive oil for the dressing (see pantry for both amounts). Season with salt and pepper.

Just before you're ready to serve, add the rocket and apple to the dressing. Toss together.