
Bring a medium saucepan of water to the boil with 1/2 tsp of salt. Chop the potatoes into 2cm chunks (no need to peel). Trim the green beans. Grate the cheese. Put the onion marmalade into a bowl and use a spoon to break it up.
Sandwich each chicken breast between two pieces of clingfilm. Bash the chicken with a rolling pin or the bottom of a saucepan until it is 2cm thick all over. IMPORTANT: Wash your hands after handling raw meat. Once the water is boiling, add the potatoes and garlic clove(s) and cook until tender, 15-20 mins. TIP: The potatoes are cooked when you can easily slip a knife through them. Once cooked, drain in a colander, pop back into the pan and cover with a lid to keep warm.
Meanwhile, heat a drizzle of oil in a frying pan on medium-high heat. Season the chicken with salt and pepper. Once the pan is hot, lay in the chicken, fry until golden brown, 5-7 mins each side. TIP: when your chicken is ready to be turned, it will release easily from the pan.
Once browned, transfer the chicken to a baking tray (don't wash your pan). Divide the onion marmalade between the top of each chicken breast, use a spoon to spread it out. Divide the cheese between the tops of the breasts, press it down with the back of a spoon. Heat your grill to high. When hot, grill the chicken until the cheese is golden and bubbly, 3-5 mins. IMPORTANT: The chicken is cooked when no longer pink in the middle. Allow to rest for 2 mins before serving.
While the chicken is grilling, pop your (now empty) frying pan back on medium-high heat and add a drizzle of oil. Once the pan is hot, add the green beans, season with salt and pepper and stir-fry until starting to char, 2-3 mins. Turn the heat down to medium then add a splash of water and immediately cover with a lid or some tin foil. Allow to cook until the beans are tender, 4-5 mins. Remove the pan from the heat.
Meanwhile, once the potatoes are cooked and back in their pan, add a knob of butter and a splash of milk (if you have any) and mash until smooth. Season with salt and pepper. Once everything is ready, serve the chicken with the garlic mash and stir-fried beans. Pour over any cooking juices from the tray, add a dollop of mayo and enjoy!