Preheat your oven to 200°C.
Chop the potatoes into 2cm chunks (no need to peel).
Pop onto a large baking tray. Drizzle with oil, season with salt and pepper then toss to coat. Spread out in a single layer. TIP: Use two baking trays if necessary.
When the oven is hot, roast on the top shelf until golden, 25-35 mins. Turn halfway through.

Meanwhile, peel and grate the garlic (or use a garlic press). Trim and thinly slice the spring onion.
Sandwich each chicken breast between two pieces of baking paper or cling film.
Pop onto a board, then give it a bash with the bottom of a saucepan until it’s 1-2cm thick. IMPORTANT: Wash your hands and equipment after handling raw chicken and its packaging.

Heat a drizzle of oil in a large frying pan on medium-high heat. Season the chicken with salt and pepper.
Once the pan is hot, lay in the chicken. Cook until golden brown, 5-6 mins each side. IMPORTANT: The chicken is cooked when no longer pink in the middle.

While the chicken cooks, pick the tarragon leaves from their stalks and finely chop (discard the stalks).
Once the chicken is cooked, lower the heat to medium and add the garlic. Cook for 1 min.
Stir in the creme fraiche, water for the sauce (see ingredients for amount) and chicken stock paste, then bring to a simmer and bubble gently until the sauce has thickened, 2-4 mins.
Remove from the heat, then stir through the tarragon.

While the sauce simmers, heat a drizzle of oil in a small saucepan on medium-high heat.
When the pan is hot, add the spring onion and cook for 1-2 mins. Add the peas and stir-fry until piping hot, 2-3 mins. Season with salt and pepper.

When everything is ready, slice the chicken widthways, then transfer to your plates and spoon over the creamy tarragon sauce. TIP: Add a splash of water and warm through if it's a little thick.
Serve the roasted potatoes and peas alongside. Enjoy!