COOK PASTA: Cook pasta shells per box instructions. Drain and set aside to cool. 9 minutes, until not quite al dente.
PREHEAT OVEN: Move oven rack to middle position and preheat to 350 degrees F.
COOK CHICKEN: Pat cutlets dry with paper towel, and cut into 1-inch pieces. Season with salt and pepper. Dredge in flour to coat and shake to remove excess.
In large skillet over high heat, add 2 teaspoons oil and heat until just smoking. Add chicken pieces and cook until golden brown and cooked through, about 2-2 ½ minutes. Transfer chicken to medium bowl, and cover with foil.
COOK PANCETTA & MUSHROOMS: Return now empty skillet to medium-low heat and add pancetta. Cook, stirring often, until pancetta is brown and crisp, about 3 minutes. Add mushrooms and increase heat to medium-high, and cook until liquid from mushrooms evaporates, and mushroom edges begin to brown, about 6-7 minutes. Transfer pancetta and mushrooms to bowl with chicken and cover.
COOK SHALLOTS: Increase heat to medium, and add remaining 1 teaspoon oil and shallots to skillet and cook until nicely browned, about 5 minutes. Add tomato paste and garlic and cook until fragrant, about 1 minute.
MAKE SAUCE: Deglaze skillet with Holland House Marsala Cooking Wine, and simmer mixture until reduced by half, about 6-8 minutes. Whisk in chicken broth and cream. Add oregano, and season with salt and pepper. Simmer sauce, whisking often, until thickened, about 8-10 minutes (sauce should barely leave a trail when spoon runs through it).
MAKE FILLING: While the sauce simmers, make filling. In bowl of pancetta and mushrooms add chicken, ricotta, and mozzarella. Mix until just combined.
ASSEMBLE & BAKE SHELLS: Lightly grease 9x13-inch pan. Fill shells with filling, and place in pan. Ladle half of sauce over filled shells. Cover with foil and bake 20 minutes. Garnish with parsley and serve with remaining Marsala sauce.