In a large skillet over medium heat, cook chicken and mushrooms in oil for 5 minutes. Stir in soy sauce; cook 7 minutes longer. Stir in cream; simmer for 4-6 minutes or until sauce is thickened (do not boil).
In a small bowl, combine the butter and garlic; spread over the bread. Place buttered side up on an ungreased baking sheet. Broil 4-6 in. from the heat for 2-3 minutes.
Top each slice with 1/4 cup of chicken mixture. Sprinkle with cheese. Broil for 1-2 minutes or until the cheese is melted.