Preheat oven to 375°. Melt 1 Tbsp. butter in a large skillet over medium-high heat; add half of chicken, and cook 3 minutes or until browned; turn and cook 1 minute. Transfer to a plate. (Chicken will not be cooked completely.) Repeat procedure with 1 Tbsp. butter and remaining chicken. Wipe skillet clean.
Melt 2 Tbsp. butter in skillet over medium-high heat. Add shallots, and sauté 3 minutes or until translucent. Add garlic, and sauté 30 seconds. Add mushrooms; cook, stirring often, 4 to 5 minutes or until tender. Stir in sherry, and cook, stirring often, 1 minute.
Melt remaining 1/4 cup butter in a 3-qt. saucepan over medium-high heat. Whisk in flour; cook, whisking constantly, 1 minute. Gradually whisk in broth. Bring to a boil, whisking constantly, and cook, whisking constantly, 1 to 2 minutes or until slightly thickened. Remove from heat, and add rice (reserve flavor packet for another use), next 5 ingredients, and shallot mixture. Spoon into a lightly greased 13- x 9-inch baking dish or disposable foil pan. Top with chicken.
Bake at 375° for 30 to 35 minutes or until a meat thermometer inserted in thickest portion of chicken registers 165°. Remove from oven, and let stand 10 minutes. Sprinkle with almonds.