Place chicken breast between two pieces of parchment paper and pound chicken breasts to even out thickness with a mallet or the back of a small skillet. Lightly salt and pepper.
In large skillet, saute chicken in 1 tbsp. melted butter and 1 tbsp. olive oil until lightly browned, about 4 minutes per side.
Remove from pan and set aside.
Melt remaining butter and add remaining olive oil in pan and add shallots and mushrooms.
Cook until mushrooms are lightly browned and have released their juices, approximately 5-6 minutes.
Add Marsala wine and bring to a boil, scraping browned bits from bottom of pan.
Add half and half, chicken broth and lemon juice and return to a boil.
Season with salt and pepper.
Return chicken to pan for about 3 minutes to reheat and finish cooking.
Recipe by Becky's Best Bites at https://beckysbestbites.com/chicken-marsala-pasta/