Combine first 6 ingredients in a large zip-top plastic bag. Add zucchini, onion, bell pepper, 1 teaspoon vinegar, and 1/2 teaspoon olive oil; seal and shake well to coat. Let stand 30 minutes, or refrigerate overnight.
Heat remaining 1/2 teaspoon olive oil in a large nonstick skillet coated with cooking spray over medium-high heat. Add vegetable mixture, and sauté for 5 minutes or until vegetables are tender and begin to brown. Remove from heat, and keep warm.
Combine chutney and mayonnaise. Arrange bread slices on a baking sheet. Broil 1 minute or until lightly toasted on each side; remove from heat. Spread each slice with about 1 tablespoon chutney mixture; top evenly with cheese. Broil 1 minute or until cheese melts. Place 1 cheese toast on each of 4 plates; top each serving with 1/4 cup greens and 1/2 cup vegetable mixture.