With an electric mixer combine the mustard, honey, and 1 Tbsp oil, and lemon juice for 1 minute.
Pour 1/2 mixture over chicken in a gallon ziplock to marinate in fridge 2-24 hours.
Chill remaining marinade to serve with chicken.
After marinating chicken, Put remaining oil in frying pan. Sear chicken on both sides until cooked thru.
Transfer chicken to a pan and brush with marinade; keep warm.
Meanwhile in frying pan add butter and saute mushrooms. Remove from the heat.
Cut chicken into bite size pieces and line your ingredients up, this part will go quickly! Chicken, cheese, mushrooms and bacon.
If you have a quesadilla maker get it heated up, otherwise, heat a frying pan and to medium heat and spread a little butter or non stick spray on the bottom.
Prepare tortillas by spreading a little butter on the ousides.
Place a tortilla, butter side down and add chicken, mushrooms, bacon and then the cheese but DO NOT OVERFILL. Place the other tortilla on top, butter side up. Flip (carefully) once bottom side is golden and do the same to the remaining side.