Heat oil and butter in a skillet over medium heat. Add chopped onions and sauté them for about 3–4 minutes until they become translucent and fragrant.
Once the onions are ready, add in the broccoli florets and continue cooking for an additional 2 minutes, allowing them to soften slightly while maintaining their vibrant color.
Stir in minced garlic along with Italian seasoning and orzo pasta, toasting it all together for about 30 seconds until aromatic, which helps deepen the flavors.
Pour in chicken broth, heavy cream, and Worcestershire sauce; bring everything to a boil before reducing heat to simmer gently while stirring frequently.
After about 10 minutes of cooking uncovered, add cooked shredded chicken into the pot, stirring well until heated through and combined evenly with other ingredients.
Remove from heat before stirring in shredded cheddar cheese until melted completely; season with salt and pepper as desired then let sit for 2–3 minutes to thicken before serving warm.