1. Preheat the oven to 180°C (350°F). Grease a gratin dish and rub one of the two cloves of garlic, cut in half, against the edges.
2. Season the chicken on both sides with salt and pepper. In a large skillet with high sides, brown the chicken in a little olive oil for 3-5 minutes on each side until golden. Transfer to the gratin dish.
3. Slice two lemons. In the same skillet used for the chicken, melt the butter and brown the lemon slices on both sides over medium heat. Add to the chicken.
4. Peel and crush the remaining garlic clove, and sauté it with a little olive oil and the rice in the same skillet. After 2 minutes, add the two bouillon cubes and 500ml (2 cups) of water.
5. Wash and roughly chop the spinach, then add it to the skillet along with the zest and juice of the remaining lemon. Sauté everything for 5 minutes, then add it to the chicken and lemon slices, mixing well. Cover with water.
6. Bake for 20 minutes: make sure to check regularly and add a little water if necessary from time to time to ensure the rice cooks well. Once cooked, add the chopped coriander.