Ingredients:

4 oil-packed sun-dried tomatoes,drained
1/2 cup mayonnaise
1 tablespoon whole-grain Dijon mustard
8 ounces andouille sausages,cut into 1-inch pieces
2 1/2 pounds ground beef (15% fat)
2 large shallots, minced
2 teaspoons salt
2 teaspoons ground black pepper
1 teaspoon fennel seeds,crushed
6 large sesame-seed hamburger buns
6 1/3-inch-thick slices red onion
Olive oil
1 cup coarsely grated Asiago cheese
1 7- to 7 1/2-ounce jar roasted red peppers,drained

Methods:

Finely chop sun-dried tomatoes in processor. Blend in mayonnaise and mustard. Transfer to small bowl. (Can be made 1 day ahead. Cover; chill.)

Finely chop andouille sausages in processor. Transfer to large bowl. Add beef, shallots, salt, pepper, and crushed fennel seeds. Stir with fork just until blended. Form mixture into six 1-inch-thick patties.

Prepare barbecue (medium-high heat).Grill hamburger buns until golden,about 2 minutes. Transfer to platter. Brush onion slices with oil.Sprinkle with salt and pepper. Grill until golden, about 7 minutes per side.Grill hamburgers to desired doneness,about 5 minutes per side for medium-rare. Sprinkle cheese over top of burgers.

Spread cut sides of hamburger buns with sun-dried-tomato mayonnaise.Top bottom halves of buns with hamburgers,then red peppers.Top with onion slices.Cover with top halves of buns and serve.