Preheat your oven to 375°F and lightly grease a baking sheet.
Toast Panko (Optional)
Heat a medium skillet over medium heat. Lightly grease with cooking spray or about a teaspoon of cooking oil. Add panko and toast, stirring almost constantly once it begins to brown, until golden in color, about 5 minutes. Transfer panko to a medium container large enough to dip a chicken breast into and set aside.
Butterfly each chicken breast by placing one hand flat on the top of the breast and slicing horizontally almost all the way through, so you have thin, even pieces on the top and bottom and you can open it like a book.
In a medium container, large enough to dip a chicken breast, crack and whisk egg, set aside.
Into the panko, stir Italian seasoning, salt, and pepper.
Dip closed chicken breasts first in the egg then in the panko, coating the top and bottom, and place on prepared baking sheet. Don’t discard any extra panko.
Open chicken breasts and place 4 spears of asparagus inside of each and top each with 1/4 cup of cheese. Close chicken breasts and sprinkle any remaining panko over the top.
Bake for 25 to 35 minutes, until an instant-read thermometer inserted into the thickest part of the breast reads 165°F. Allow chicken to rest for at least 5 minutes before serving. Enjoy!
*You can also use regular bread crumbs. If using bread crumbs, skip the toasting step and go right to coating the chicken.