On a cutting board, using a sharp knife, dice the green bell pepper, Florina pepper, carrot, and zucchini into small cubes. Finely chop the onion, leek, and garlic.
Heat a non-stick pan over high heat until very hot and add half of the olive oil.
Sear the chicken thigh fillets on both sides until nicely browned, seasoning with salt and freshly ground black pepper.
Once the chicken is ready, remove it from the pan and place it in an ovenproof dish. Return the pan to high heat and add the remaining olive oil.
Sauté the vegetables for 3–4 minutes until softened and lightly caramelized, seasoning with salt and freshly ground black pepper. Deglaze with the white wine and, once it has evaporated, add the vegetables to the ovenproof dish with the chicken.
Bring the chicken stock to a boil and add it to the ovenproof dish along with the lemon zest and juice, orzo pasta, salt, and freshly ground black pepper. Mix well.
Bake in a preheated oven at 200°C (fan-assisted) for 30–35 minutes.
Once the giouvetsi is ready, remove it from the oven, sprinkle with the chopped parsley, give it one final stir, and serve.
