Dice the onion into small, fine pieces. Chop the sundried tomatoes into small pieces (keep the olive oil with the tomatoes). For the turkey burgers, mix together the turkey, diced onion, chopped sundried tomatoes, chopped kale, seasonings and panko in a large mixing bowl. Once the mixture is combined, form into 3-4 inch wide patties.
For the sundried tomato spread, heat the cream cheese in a microwave safe bowl until soft. Mix with a fork until smooth. Add the rest of the ingredients and set aside until ready to serve.
If you want carmelized onions and mushrooms with your burger you can slice those and saute in some olive oil until soft. Season with salt and pepper.
Grill the burgers on a hot outdoor or indoor grill, or on a flat griddle. Cook the burgers on one side until golden brown and then flip to the other side. Continue to cook until the center of the burgers is no longer pink.
Spread one side of the hamburger bun with the sundried tomato spread. Place the burger on the bun and top with lettuce, tomatoes and the sauted onions and mushrooms. If you like balsamice glaze, you can drizzle that on as well. Serve warm.
*For a lower carb version, serve on lettuce instead of a bun.