Wash and dry all produce. Bring 2 cups water and a large pinch of salt to a boil in a medium pot. Once boiling, add the rice. Cover and reduce to a low simmer for 20 minutes, until tender. Halve the zucchinis lengthwise, then thinly slice into half-moons. Thinly slice the mushrooms. Mince the garlic. Finely chop the parsley. Halve, peel, and mince the shallots.

In a large pan, heat a large drizzle of oil over high heat. Add the zucchini. Cook, tossing, for 7-10 minutes, until golden brown. Season with salt and pepper. Remove pan from heat.

Place your hand on top of the chicken breast. Slice into the middle of the meat (parallel to the cutting board). Open up like a book, then cover with a piece of plastic wrap. Pound with a heavy pan or mallet until 1/2-inch thick. Repeat with the other chicken breasts. Season the chicken with salt and pepper. Set aside 1/4 cup flour. Coat the chicken on all sides with the remaining flour, shaking of any excess. Heat a large drizzle of oil in another large pan over medium-high heat. Working in batches, if necessary, sear the chicken 2-3 minutes per side, until golden brown and cooked through. Remove from pan and set aside to rest, tented loosely with foil.

Heat 2 Tablespoons butter in the same pan over medium-high heat. Add the mushrooms. Cook, tossing, for 4-5 minutes, until softened. Add the shallots, garlic, and 2 additional Tablespoons butter to the pan. Cook 1-2 minutes, until fragrant.

Finish the Marsala sauce: Add the reserved 1/4 cup flour to the pan. Cook, stirring, for 1 minute. Whisk the stock concentrates and 1 cup water into the pan until the sauce thickens. Reduce heat to low, and stir in the sour cream and half the parsley. Season with salt and pepper.

Plate: Reheat the zucchini if necessary. Serve the chicken cutlets on a bed of basmati rice alongside the zucchini. Spoon the Marsala sauce over the plate, garnish with the remaining parsley, and enjoy!