Step 1: Bring a large pot of salted water to a boil and cook the pasta according to the package instructions until al dente.
Step 2: While the pasta boils, heat olive oil in a large skillet over medium-high heat. Season the chicken pieces with salt and pepper, then add to the skillet.
Step 3: Sear the chicken for 5-7 minutes, turning occasionally, until golden brown and cooked through. Remove the chicken from the skillet and set aside.
Step 4: Before draining the pasta, reserve 1 cup of the starchy pasta water. Drain the rest of the pasta.
Step 5: Reduce the skillet heat to medium. Add the Boursin cheese and 1/2 cup of the reserved pasta water. Stir continuously until the cheese melts into a smooth, creamy sauce.
Step 6: Add the cooked pasta and chicken back into the skillet. Toss well to coat every piece in the sauce, adding more pasta water if the sauce is too thick.
Step 7: Serve immediately, garnished with fresh parsley if desired.