Take your chicken tenderloins and put them into a sealable plastic bag and pound until flattened to about ½ inch to help with even cooking. Dry well. Season both sides with salt and pepper, paprika and thyme. Set aside.
In a frying pan add your olive oil and fry up chopped onions and fry until translucent. Add garlic to the pan. Move the onions to the edges of the pan and add your sliced mushrooms and season with salt and pepper and cook until slightly golden. (You may need to add more oil at this point as mushrooms always absorb anything in the pan).
Step 3: Add your seasoned chicken tenderloins to the pan and cook on both sides until golden brown about 2 minutes each side. Remove the pan from the burner (heat) and add the brandy and then put pan back on the burner on a low medium heat and stir the bottom of the pan to loosen all of those delicious brown bits on the bottom of the pan. Add the chicken broth and turn the heat on to a low simmer and let the chicken cook for about 6-8 minutes and/or the sauce reduces to about ½ and/or until the chicken is no longer pink inside.
Add the cornstarch to the water to make a cornstarch slurry, stir. Slowly add a little of the corn starch slurry( at little a time) while whisking the brandy gravy just until it coats the back of the spoon. You may not need all of the cornstarch slurry mixture. Taste and adjust seasoning. Remove the mushroom chicken with Brandy sauce from the heat source and add the butter (or butter alternative) and stir until mixed well.
Garnish with parsley or fresh thyme and enjoy!
Notes
We used button mushrooms but you can exchange with any mushrooms of choice.