In a large skillet, heat 2 tablespoons of oil over medium-high heat. Season chicken breasts with salt and pepper, then add them to the skillet. Cook for about 6 minutes per side until golden brown and cooked through. Transfer the chicken to a plate and let it rest.

In the same skillet, reduce heat to medium and melt 2 tablespoons of butter. Add diced onion and broccoli florets, sautéing until softened, about 5–7 minutes. Stir in 2 minced garlic cloves and cook for an additional minute until fragrant.

Add 1 cup of orzo to the skillet, stirring well to coat it in the buttery vegetable mixture. Pour in 4 cups of chicken stock and bring to a gentle simmer. Cook uncovered for about 10–11 minutes until orzo is tender and most of the liquid has been absorbed.

Reduce heat to low and stir in 1 cup each of shredded Parmesan and cheddar cheese, mixing until melted and creamy. Return chicken to the skillet, allowing it to warm through.

Remove the skillet from heat, drizzle with 2 tablespoons of fresh lemon juice, and mix well. Adjust seasoning with additional salt and pepper to taste. Garnish with freshly chopped herbs before serving.