Andouille and Beef Burgers with Spicy Mayo and Caramelized Onions

Name: Andouille and Beef Burgers with Spicy Mayo and Caramelized Onions
Ingredients: 3 /4 cup mayonnaise; 1 teaspoon fresh lemon juice; 1 teaspoon Cajun or Creole seasoning blend; 1 /4 teaspoon hot pepper sauce; 1 /2 pound andouille sausage, cut into scant 1/4-inch cubes; 3 /4 cup pecans, toasted, chopped; 1 teaspoon salt; 1 /4 teaspoon ground black pepper; 1 1/2 pounds ground beef chuck or ground beef (20 percent fat); 1 1/2 pounds onions, thinly sliced; 2 tablespoons olive oil plus more for brushing grill rack; 3 click on heregarlic cloves, minced; 1 tablespoon golden brown sugar; 6 large hamburger buns, split; 8 ounces crumbled blue cheese; 12 pickled okra pods, halved lengthwise; 3 cups watercress tops