For the chicken: Season the chicken breast strips with the salt and pepper. Sprinkle with the flour and toss to coat on all sides.
In a small baking dish, combine the Greek yogurt and chipotle powder if using. Whisk to combine. In a second small baking dish, combine the breadcrumbs, garlic powder and mustard powder. Coat each chicken strip in the yogurt mixture and then the breadcrumb mixture. Place the strips on a wire rack set over a rimmed baking sheet. Repeat until all the strips are completely coated in breadcrumbs. Spray the chicken strips with cooking spray and bake until golden and crunchy and the center is cooked through, 10 to 13 minutes.
While the chicken bakes, make the dip: Whisk together the creme fraiche, mayonnaise, lemon juice, basil, parsley, chives and thyme in a medium bowl. Season with salt and pepper and refrigerate until ready to serve.