In a small saucepan, bring water to a boil; add dried mushrooms. Remove from heat; let stand 25-30 minutes or until softened., Using a slotted spoon, remove mushrooms; rinse. Trim and discard stems from shiitake mushrooms. Chop mushrooms. Strain soaking liquid through a fine-mesh strainer. Reserve mushrooms and soaking liquid., In a Dutch oven, heat butter over medium-high heat. Add onion; cook and stir until tender. Add fresh and baby portobello mushrooms; cook and stir until tender. Add garlic; cook 1 minute longer., Stir in broth, rice mix with contents of seasoning packet, reserved dried mushrooms and soaking liquid, salt and pepper. Bring to a boil. Reduce heat; simmer, covered, 20-25 minutes or until rice is tender., In a small bowl, mix water and cornstarch until smooth; stir into soup. Bring to a boil; cook and stir 2 minutes or until thickened. Stir in cream; heat through.