Clean and prepare chicken breast first by trimming any fat, pat dry with a paper towel, and then slice the chicken in half, lengthwise. You’ll turn 1 thick chicken breast into two thinly sliced breasts.
Season sliced chicken breasts on each side with salt and pepper.
Then, evenly space the chicken while on the cutting board and cover with plastic wrap.
Tenderize the meat with a meat pounder. This will not only tenderize the chicken, but also ensure all pieces are the same thickness and will cook evenly.
Heat 1 tablespoon of cooking oil in a large skillet over medium high heat with 1 tablespoon of the sun dried tomato oil from the jar.
Carefully place chicken into the skillet and cook until golden brown on each side, cooked through and no longer pink. Transfer chicken to a plate and set aside.
Reduce heat to low-medium heat and saute mushrooms in same pan until soft. Add more oil, if needed.
Slowly add in the heavy cream, butter, and Parmesan cheese to the skillet and stir until the butter and cheese melts. Bring to a simmer for 3 to 4 minutes.
Once combined, add garlic to the sauce in the skillet and cook until fragrant, stirring occasionally.
Add a pinch of salt and pepper to taste along with the oregano.
Simmer for another 2 minutes, or until sauce starts to thicken. Add more grated Parmesan cheese if the sauce needs a little help to thicken!
Add the sliced sun-dried tomatoes, fresh spinach and the cooked chicken breast back into the pan and combine ingredients well. Stir until heated through.
Serve immediately over cooked pasta.