Melt butter in a nonstick skillet over medium-high heat. Add mushrooms; cook 5 minutes or until tender. Add soy sauce; cook 1 minute. Remove mushrooms from skillet.
Sprinkle patties with garlic salt. Cook patties in skillet over medium-high heat 5 to 6 minutes per side or until no longer pink. Top each patty with cheese; cook 1 minute longer.
Spoon mushrooms over patties.
Grilled Zucchini And Squash
Preheat grill to medium-high heat. Brush zucchini and squash with oil; sprinkle with garlic salt.
Grill 6 to 8 minutes per side or until tender. Remove from grill; cool slightly, and slice.