While the chicken is roasting, place the potatoes into a pot of cold water over medium-high heat. Bring the water to a bubble and cook the potatoes until tender, about 10 minutes depending on their size. Drain the potatoes and return them to their cooking pot to dry off and cool down slightly. Add a splash of chicken stock, the ricotta, grated Parmigiano and parsley to the potatoes and smash them. Place with the lid on the pot to keep them warm and reserve.
When the chicken is about halfway done, arrange the green beans on a cookie sheet. Drizzle them liberally with some EVOO and season with some salt and pepper. Place in the oven with the chicken and roast for about 15 minutes, until tender.
When the chicken is almost done, place a medium-size pot over medium heat and melt the butter. Sprinkle the flour over the butter and cook it for about 1 minute. Whisk the chicken stock into the roux along with the thyme. Season the gravy with salt and freshly ground black pepper, and a splash of lemon juice.
To serve, place a few pieces of chicken per person on each plate along with some of the mashed potatoes and roasted green beans alongside, topping everything off with some of the lemon-thyme gravy.