1. Bring 4 cups water to a boil in a large straight-sided skillet. Add 1/2 teaspoon salt and green beans. Reduce heat to medium; cook 6 minutes or until tender. Drain beans; rinse with cold water. Drain and set aside.
2. Wipe skillet clean and dry with paper towels; return skillet to medium-high heat. Add oil to pan; swirl to coat. Add sliced onion; sauté 5 minutes or until lightly browned, stirring occasionally. Add mushrooms; sauté 3 minutes or until mushrooms brown, stirring occasionally. Add sherry and thyme; sprinkle with remaining 1/4 teaspoon salt. Bring to a boil; cook until liquid almost evaporates. Stir in flour; cook 30 seconds, stirring constantly. Add cream cheese; stir until cheese melts. Stir in stock; bring to a boil, stirring constantly. Cook 2 minutes or until slightly thick. Remove from heat. Add beans; toss to coat. Sprinkle with crushed onions.