Preheat your oven to 220°C/200°C fan/gas mark 7. Put a large saucepan of water on to boil with 1/2 tsp salt.
Put the breadcrumbs, oregano and olive oil for the crumb (see ingredients for amount) into a small bowl. Season with salt and pepper and mix well.
Pop the chicken breasts onto a baking tray and season them well. Spoon a quarter of the mayo over the top half of each breast. Sprinkle over the crumb mixture and press it down with a spoon. IMPORTANT: Wash your hands and equipment after handling raw chicken and its packaging.

When the oven is hot, roast the chicken on the top shelf until cooked through and golden on top, 25-30 mins. TIP: Cover the chicken with foil if the crumb is browning too quickly. IMPORTANT: The chicken is cooked when no longer pink in the middle.

While the chicken roasts, chop the potatoes into 2cm chunks (peel first if you prefer).
Trim the green beans. Peel and grate the garlic (or use a garlic press).
Grate the Cheddar cheese.

When your pan of water is boiling, add the potatoes and cook until you can easily slip a knife through, 15-20 mins.
Once cooked, drain in a colander and return to the pan, off the heat. Add a knob of butter and a splash of milk (if you have any) and mash until smooth.
Season with salt and pepper, then stir in the cheese. Cover with a lid to keep warm.

When the chicken has 10 mins of cooking time left, heat a drizzle of oil in a frying pan on medium-high heat.
Once hot, add the green beans and stir-fry until starting to char, 2-3 mins. Stir in the garlic, then turn the heat down to medium and cook for 1 min.
Add a splash of water and immediately cover with a lid or some foil. Allow to cook until the beans are tender, 4-5 mins. Remove the pan from the heat.

When everything is ready, slice the chicken widthways and serve on your plates with the mash and beans alongside.
Serve with the remaining mayo for dipping
Enjoy!