Preheat oven to 375°F. In a large skillet over medium-high heat, heat oil. Cook shallots, carrots and Brussels sprouts until starting to soften, stirring occasionally, 6 to 8 minutes.
In a large bowl, combine cooked vegetables, cooked chicken, cooked rice mix, garlic, oregano, thyme, salt and Creamy Casserole Sauce. Stir until well mixed and transfer to a 2 ½-quart casserole dish.
Bake, covered, for 25 minutes. Uncover and stir; sprinkle with topper. Bake, uncovered, for 10 to 15 minutes more or until casserole is heated through and topper is golden brown.