The Brown Derby's Cobb Salad

Name: The Brown Derby's Cobb Salad
Cuisine: American
Ingredients: 1 head iceberg lettuce, finely chopped; 1 bunch watercress, finely chopped; 2 avocados, chopped; 2 hard-boiled eggs, finely chopped; 6 green onions, finely chopped; 2 tomatoes, chopped; 3 cups chopped cooked chicken breast; 8 slices bacon, fried, drained, and crumbled; 3 ounces Roquefort cheese, crumbled; 1-1/2 cups salad oil; ½ cup white vinegar; 1 Tablespoon freshly squeezed lemon juice; ½ teaspoon freshly ground black pepper; ½ teaspoon dry mustard; 1 teaspoon Worcestershire sauce; 1 clove garlic, pressed; ½ teaspoon salt; 1 teaspoon sugar