Heat the oil in a 12-inch skillet over medium-high heat. Add the chicken and cook for 15 minutes or until it's well browned on both sides and cooked through. Remove the chicken from the skillet.
Add the shallots and garlic to the skillet and cook until they're tender. Stir in the stock, syrup, mustard and pepper and heat to a boil. Reduce the heat to low. Cook for 10 minutes or until the stock mixture is slightly thickened and reduced to about 1 cup. Serve the stock mixture over the chicken.