Bring 1 cup Marsala, gelatin, and porcini mushrooms to boil in small saucepan over high heat.
Reduce heat to medium-high and vigorously simmer until reduced by half, 4 to 6 minutes.
Pound chicken breasts to an even 1/2-inch thickness.
Place cutlets in a ZipLock bag and toss thoroughly with 1 teaspoon salt (and 1/4 teaspoon pepper, if desired) Set aside for 15 minutes.
Strain Marsala reduction through fine-mesh strainer, pressing on solids to extract as much liquid as possible; discard solids.
Return Marsala reduction to saucepan, add broth, and return to boil over high heat.
Lower heat to medium-high and simmer until reduced to 3/4 cup, 8 to 10 minutes. Set aside.
Spread flour in shallow dish and dredge chicken in flour, shaking gently to remove excess and place on wire rack set in rimmed baking sheet.
Heat 2 tablespoons oil in 12-inch skillet over medium-high heat until smoking.
Place cutlets in skillet and lower heat to medium.
Cook until golden brown on 1 side, 2 to 3 minutes. Flip and cook until golden brown on second side, 2 to 3 minutes. Return cutlets to wire rack. Don’t worry if they are not cooked through, they will finish in the sauce.
Return now-empty skillet to medium-low heat and add pancetta.
Cook pancetta (or chopped up bacon), stirring occasionally, scraping pan bottom to loosen browned bits, until pancetta is brown and crisp, about 4 minutes.
Add cremini mushrooms and increase heat to medium-high.
Cook, stirring occasionally and scraping pan bottom, until liquid released by mushrooms evaporates and mushrooms begin to brown, about 8 minutes.
Using slotted spoon, transfer mushrooms and pancetta to bowl.
Add remaining 1 teaspoon oil and shallot to skillet and cook until softened, 1 minute.
Add tomato paste and garlic and cook until fragrant, 30 seconds.
Add reduced Marsala mixture, remaining 1/8 cup Marsala, lemon juice, and oregano and bring to simmer.
Add cutlets to sauce and simmer for 3 minutes to 165˚F internal temperature, flipping halfway through simmering.
Transfer cutlets to platter.
Off heat, whisk in butter.
Stir in parsley and cremini mushroom mixture.
Season with salt and pepper to taste.
Top with finely shredded fresh Paresan cheese.
Spoon sauce over chicken and serve.