Slice the chicken breasts in half to create thinner pieces. Season both sides with garlic powder, salt, and pepper.
Heat olive oil and butter in a large skillet over medium-high heat. Add the chicken and cook for about 4-5 minutes per side until golden brown. Remove and set aside.
In the same skillet, add diced onions. Sauté for 2-3 minutes until softened.
Pour in the chicken broth and stir. Add the Boursin cheese, stirring constantly until the sauce becomes smooth and creamy. Simmer for 2-3 minutes.
Return the chicken to the skillet, coating it in the sauce. Let it warm through for about 2 minutes.
Garnish with fresh parsley and serve hot over mashed potatoes, rice, or pasta.