Preheat your oven to 220°C/200°C fan/gas mark 7.

Chop the potatoes into 2cm chunks (no need to peel), then add to a large baking tray. Drizzle with oil, sprinkle over the dried oregano, then season with salt and pepper. Toss to coat. Spread out in a single layer. TIP: Use two baking trays if necessary.

When the oven is hot, roast on the middle shelf until golden, 30-40 mins. Turn halfway through.

In the meantime, peel and grate the garlic (or use a garlic press). Trim the root and dark green leafy part from the leek and discard. Halve lengthways, then thinly slice.

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

Once hot, lay the chicken flat in the pan. TIP: Notice a stronger smell from your chicken? Don’t worry, this is normal due to packaging we use to keep it fresh. IMPORTANT: Wash your hands and equipment after handling raw chicken and its packaging.

Fry until browned all over, 5 mins each side. 

Once the chicken has browned, pop it onto a baking tray lined with foil. Bake on the top shelf of your oven until cooked through, 10-12 mins. IMPORTANT: The chicken is cooked when no longer pink in the middle.

When the potatoes have 10 mins remaining, return the (now empty) chicken pan to medium-high heat with a drizzle of oil.

Once hot, add the leek and season with salt and pepper. Cook the leek until softened, 4-6 mins, stirring occasionally.

Meanwhile, when the potatoes have 5 mins of roasting remaining, remove the tray from the oven, add the peas and toss to coat. Return the tray to the oven for the remaining cook time until the peas have warmed through, 5-6 mins.

Add the garlic to the leeks and stir-fry, 1 min more. Season with salt and pepper. 

Add the creme fraiche, pesto and water for the sauce (see pantry for amount). Stir to combine, bring to a boil, then lower the heat and simmer until piping hot, 1-2 mins.

Add a splash of water if it's a little too thick.

When everything's ready, slice the chicken breasts into 2cm thick slices and share between your serving plates.

Serve the roasted potatoes and peas alongside.

Finish by spooning the creamy leek and pesto sauce over your chicken.