Combine first 4 ingredients, 1/4 teaspoon salt, and 1/2 teaspoon pepper in a small bowl, stirring with a whisk. Gradually add 3 1/2 tablespoons oil, stirring with a whisk.
Heat a large nonstick skillet over medium-high heat.
Add 1 tablespoon oil; swirl to coat.
Add bread cubes to pan; sprinkle with 1/8 teaspoon salt. Cook 4 to 5 minutes or until crunchy and golden, stirring occasionally.
Remove from heat.
Preheat grill to medium-high heat.
Brush chicken with remaining 1 1/2 teaspoons oil; sprinkle with remaining 1/4 teaspoon salt and remaining 1/4 teaspoon pepper.
Place chicken on grill rack; grill 6 minutes on each side or until done.
Let stand 5 minutes; cut into thin slices.
Place lettuce in a large bowl; drizzle with dressing.
Sprinkle with cheese; toss to coat.
Place about 1 3/4 cups lettuce mixture on each of 4 plates; top each with 1/3 cup croutons and 3 ounces chicken.