Cut the chicken breasts into small bite-sized cubes and slice the mushrooms. Chop the onion into small cubes.
Season the chicken with salt, pepper and garlic powder. Heat 1 tbsp of olive oil and 1 tbsp of butter in a large skillet and fry the chicken until cooked and golden. Remove the chicken from the skillet.
In the same skillet add 1 tbsp of olive oil and 1 tbsp of butter. Add the onion and cook until translucent. Then add the sliced mushrooms and season with salt, pepper and dried thyme, and cook until all the liquid from the mushrooms is gone and they are golden.
Then add flour and mix it in well. Cook for about one minute stirring frequently. Then add cold chicken broth and stir well. Bring to a boil and let it simmer until the sauce thickens up.
While the sauce is simmering, boil pasta according the instructions on the package until al dente.
When the pasta is almost ready, add cream to the sauce and return the chicken to the skillet. Drain the pasta and add it too. Mix well so the pasta is fully coated with the sauce. Plate, garnish with fresh parsley and serve immediately.
Notes
Instead of chicken breasts you can use chicken thighs. However, have in mind that they have a bit more fat than chicken breasts.
If you wish to use a different type of cream, try to stick to mildly flavored creams and avoid those with stronger flavors, such as sour cream.