Take your poultry out of the cold refrigerator. Let it rest on the kitchen counter for roughly ten minutes. Pat the meat entirely dry using clean paper towels, then season both sides very generously with kosher salt and black pepper.
Place your large, heavy skillet over medium heat. Pour in the extra virgin olive oil and wait until the oil shimmers slightly. Lay the seasoned pieces into the hot oil and let them cook undisturbed for 5 to 6 minutes.
Flip them over quickly and cook the second side for another 5 minutes until completely done. Transfer the cooked meat to a clean plate and tent loosely with aluminum foil.
Do not wipe out the hot pan! Drop your butter directly into the skillet. Once melted, toss in the thinly sliced shallot and stir continuously for about 2 minutes until very soft and slightly translucent.
Add all your sliced mushrooms to the warm skillet in a single, even layer. Cook entirely without stirring for two full minutes to develop a brown crust. Toss and continue cooking until they release their natural juices. Sprinkle with fresh chopped sage, a pinch of salt, and pepper.
Pour your Marsala liquid substitute blend directly over the hot vegetables. Use a wooden spoon to scrape the pan bottom thoroughly, lifting the browned bits. Let the liquid reduce by at least half.
Pour in your measured chicken broth followed by the heavy whipping cream. Stir gently to combine and bring to a gentle boil. Turn the heat down to a very low simmer and let it cook uncovered until it thickens slightly (it should briefly leave a clean trail when dragging a spoon through it).
Pour any accumulated meat juices from the resting plate directly into the simmering sauce. Nestle the golden chicken pieces back into the gravy. Baste the meat and let everything simmer for 3 to 5 more minutes until the internal temperature reaches 165 degrees Fahrenheit.
Turn off the burner, garnish with extra fresh chopped sage, and serve over cauliflower rice, zucchini noodles, or roasted green asparagus.