For the sauce, melt the butter in a sauté pan over medium to medium-high heat and add the rhubarb. Sauté for a couple of minutes to get it going, then pour the sugar around the pan, season the rhubarb with a little sea salt and nutmeg, throw in a cinnamon stick and the blueberries, lemon zest and juice and stir occasionally, cooking until the berries burst, a sauce forms and the rhubarb is tender, about 20 minutes. Remove the cinnamon stick before serving.
For the rice, melt the butter over medium heat in a rice pot. Add the shallot and stir for 2 minutes, then add the orzo and toast to golden. Add the rice and 2 cups stock; bring to a boil, then reduce the heat to a simmer and cover. Cook to tender, 16-18 minutes, adding a little more stock if the rice begins to stick and is not yet tender. If using fresh peas, add them in midway in the cooking time; if you are using defrosted frozen peas, add them in when the rice is nearly done, during the last 2-3 minutes. Fluff the rice with a fork and stir in the mint and parsley.
For chicken or chops, season well with salt and pepper. Heat 1 tablespoon EVOO in a large nonstick skillet over medium-high heat. Cook for 6 minutes on each side; add stock to the pan to deglaze. Turn the meat to coat, then turn off the heat, cover with loose foil and let rest for 5 minutes.
For the spinach, heat a drizzle of EVOO over medium heat. Wilt the spinach into the pan in large handfuls; season with salt, pepper and nutmeg, to taste, then douse with the lemon juice.
Serve the chops or chicken with the “blubarb” sauce on top and the rice and peas and wilted spinach alongside.