To prepare omelet, combine the first 7 ingredients in a small bowl, stirring with a whisk. Lightly spoon flour into a dry measuring cup; level with a knife. Add flour to egg mixture; stir well.
Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add onion to pan; sauté 7 minutes or until browned. Add garlic; sauté 1 minute. Pour egg mixture over onion mixture in pan. Reduce heat, and cook 3 minutes or until set. Loosen omelet with a spatula, and fold in half; cook 1 minute. Cut omelet in half; place one half on each of 2 plates.
To prepare salad, combine salad greens, vinegar, and oil; toss well. Arrange 1 1/2 cups greens on top of each serving; top each serving with 1 tablespoon cheese and 3/4 teaspoon almonds.