Cut chicken breasts into bite-size pieces. Season generously with salt & pepper.
Heat a large skillet over medium to medium-high heat, add olive oil. When oil is heated, add the chicken and cook, stirring occasionally, until chicken is browned on all sides. Remove chicken to a plate and set aside.
To the same skillet, add 1 tablespoon of the butter. When melted, add the mushrooms and cook until they start to become golden. Add shallots, garlic, bell peppers, and herbs. Cook, stirring, until peppers start to soften, about 5-8 minutes.
Add white wine and stir for a minute, scraping bottom of pan to release flavours.
Return the chicken to the skillet, and add chicken stock, heavy cream, and pasta. Lower heat to a simmer, and cook until pasta is al dente, about 10-15 minutes depending on your choice of pasta.
Stir in grated parmesan, spinach leaves, and the rest of the butter. Stir until spinach starts to wilt, about a minute.
Finish with fresh parsley and more parmesan.