1. Preheat the oven to 425F. Grease a baking sheet.
2. Combine 3/4 cup of the mayonnaise, the onion flakes and dry mustard in a shallow bowl and mix well. Combine the cracker crumbs and sesame seeds in another shallow bowl and mix well. Dip the chicken in the mayonnaise mixture, then coat with the crumb mixture.
3. Arrange the tenders on the prepared baking sheet and bake until the chicken is no longer pink throughout, about 15 minutes.
4. Meanwhile, combine the remaining 1/2 cup mayonnaise, the sour cream, minced onion, parsley, seasoning salt and garlic powder in a small bowl and mix well. Serve with the chicken tenders.
Variation
For a more traditional dipping sauce, you can easily make honey mustard by mixing 1/4 cup honey and 2 tablespoons prepared yellow mustard.