In a large, deep frying pan, heat the oil over a medium heat. When it's hot, carefully add the chicken pieces. Cook for 5 minutes stirring occasionally until all sides are starting to colour.
Reduce the heat and add the garlic and oregano. Stir for 3-5 minutes until the garlic is softened.
Add the orzo, stock, lemon zest and plenty of pepper, give everything a good stir and put the lid on.
Cook for 10-15 minutes, or until both the chicken and orzo are cooked through, stirring occasionally. (If the mixture becomes too dry before the orzo or chicken is cooked, add a splash of water.)
Turn the heat to the lowest setting add the cream, spinach and lemon juice - continue to stir very well for 1-3 minutes until the spinach is wilted and the cream is heated through.
Turn off the heat and stir in the parmesan.
