Heat the oil in a Dutch oven over medium heat. Add the garlic, shallot, and crushed red pepper and saute until fragrant, about 30 seconds.
Add the pasta, broth, lemon zest, and lemon juice. (The broth should just cover the pasta. If it doesn't, you may need to add a little water during cooking.) Arrange the Boursin rounds in the center of the pot on top of the pasta.
Bring to a boil. Cover, reduce the heat to medium and simmer for 8 to 10 minutes or until the pasta is al dente, stirring occasionally.
Uncover and add the cream and Parmesan cheese. Simmer until the sauce is thickened.
Stir in the chicken and peas and cook just until the peas are tender, about 4 minutes. Season with salt and pepper to taste.
Divide the pasta between serving bowls or plates and sprinkle with parsley and more Parmesan if desired.