Preheat your oven to 375°F (190°C) and grease a baking dish with olive oil.
Season the chicken breasts with salt and pepper, then heat olive oil in a pan over medium-high heat.
Cook the chicken breasts until golden brown on both sides, then transfer them to the prepared baking dish.
In the same pan, melt butter and whisk in flour to create a roux.
Gradually pour in chicken broth and heavy cream, stirring constantly until the sauce thickens.
Add grated Parmesan cheese to the sauce, stirring until smooth and creamy.
Arrange broccoli florets around the chicken breasts in the baking dish.
Pour the creamy sauce over the chicken and broccoli, ensuring everything is evenly coated.
Cover the baking dish with foil and bake for 25-30 minutes, or until the chicken is cooked through and the sauce is bubbly.
Remove the foil and broil for an additional 2-3 minutes to brown the top.
Serve your Chicken Divan hot with your choice of sides.