Slice the chicken breasts right through the centre to create 4 even-sized breasts. Coat in salt, garlic powder, onion powder and black pepper.
Heat up around 1 tbsp olive oil over medium-high heat in a large deep cast iron skillet or pot. Add chicken and fry both sides until golden, with the centre piping hot and white all the way through. Remove and add to a side plate. Fry asparagus (if using) for a few mins with a good pinch of salt & pepper until they begin to soften. Add to plate with the chicken and tightly cover in foil to keep warm. Slice chicken just before needed.
Reduce heat to a medium and melt in 1 tbsp butter. Add the leek and fry until soft, then add in garlic, thyme & lemon zest and fry for another 1-2mins. Stir in orzo, then pour in chicken stock and the juice of half the lemon. Give it a stir, then stir in the cream and a pinch of salt and pepper.
Give it a good stir then bring it to a simmer. Keep the heat on low, stirring frequently until the orzo is cooked and the sauce has thickened to a risotto-style consistency. Stir in parmesan then stir in 1 more tbsp butter. Check for seasoning and adjust if desired. Stir in a splash of stock, water or cream if you over-reduce the sauce.
Serve individual portions with sliced chicken on top, alongside asparagus, a sprinkle of fresh parsley and a small lemon wedge each (if you want it more lemony).
