Heat the oven to 200C/180C fan/gas 6 and line a large baking tray with baking parchment. Combine the Dijon mustard and yogurt in a bowl and season. In a second bowl, mix the parmesan, breadcrumbs, herbs and lemon zest. Drizzle over 1 tsp of the olive oil, season and toss. Dip the chicken in the yogurt mix, then the breadcrumbs and coat well. Put on the baking tray. Toss the potatoes with 2 tsp of the oil and add to the tray. Bake for 40-45 mins until the chicken is cooked.

Meanwhile, toss the green beans in the remaining oil and season. Fry over a medium-high heat for 5 mins, until browned then squeeze in a bit of lemon juice before serving.