Preheat oven to 400 degrees. In a bowl, combine yogurt, mustards, honey, and spices. Stir together. Reserve ¼-1/2 cup sauce for dipping or salad dressing. Pour the remaining marinade into a large ziplock bag.
Slice chicken breasts diagonally into ½ inch thick strips, can also slice each strip into 3-4 chunks to make popcorn chicken that cooks quicker. Place chicken into a ziplock bag. Refrigerate in marinade for at least 30 minutes, but can leave for up to 48 hours.
Line a large baking sheet with foil. For extra crispy chicken, place wire cooling racks on top and spray with non-stick spray. This allows the bottom of the chicken to cook and crisp too. Pour the bread crumbs and flax seeds in a wide shallow bowl, or 8x8 pan.
One by one, coat the chicken with the bread crumb mixture. Do not wipe off excess honey mustard sauce before adding coating. The extra sauce helps the bread crumbs to stick. Place the breaded strips on the prepared wire wrack. Discard leftover marinade. Bake the strips until they are golden brown (about 30 minutes for strips and 20 minutes for popcorn chicken).