Ingredients

• 3/4 cup mayonnaise
• 1 tablespoon 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 garlic 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

Instructions

1. Mix all ingredients in small bowl. Cover and chill.
2. Do ahead: Can be made 2 days ahead. Keep chilled.
3. For burgers: Toss first 4 ingredients in large bowl. Add beef; blend gently. Shape mixture into six 1/2-inch-thick patties. Transfer patties to small baking sheet. Do ahead: Can be made 1 day ahead. Cover and chill.
4. Toss first 4 ingredients in large bowl. Add beef; blend gently. Shape mixture into six 1/2-inch-thick patties. Transfer patties to small baking sheet.
5. Do ahead: Can be made 1 day ahead. Cover and chill.
6. For onions: Prepare barbecue (medium-high heat). Toss onions and next 3 ingredients in large skillet. Place skillet on grill; cook until onions are golden, stirring often, about 25 minutes. Remove from grill; season with salt and pepper. Brush grill rack with olive oil. Grill buns, cut side down, until golden, about 2 minutes. Transfer buns to work surface. Grill burgers until brown on bottom, about 3 minutes. Turn over; sprinkle with cheese. Grill until burgers are cooked to desired doneness, about 3 minutes for medium. Place some onions, then burger, on each bun bottom. Top each with okra and watercress. Spread mayonnaise on cut side of bun tops; place on burgers. Serve with remaining mayonnaise.
7. Prepare barbecue (medium-high heat). Toss onions and next 3 ingredients in large skillet. Place skillet on grill; cook until onions are golden, stirring often, about 25 minutes. Remove from grill; season with salt and pepper.
8. Brush grill rack with olive oil. Grill buns, cut side down, until golden, about 2 minutes. Transfer buns to work surface. Grill burgers until brown on bottom, about 3 minutes. Turn over; sprinkle with cheese. Grill until burgers are cooked to desired doneness, about 3 minutes for medium. Place some onions, then burger, on each bun bottom. Top each with okra and watercress. Spread mayonnaise on cut side of bun tops; place on burgers. Serve with remaining mayonnaise.
9. *Shopping tip: Look for pickled okra where the pickles and relishes are displayed.