This is a recipe that I've always done with veal cutlets, and I've always finished cooking them in the sauce. This is one of those trade offs. If you finish cooking the chicken breasts in the oven, you get a nicer presentation. But, if you cook them in the sauce, you'll end up with the flavors of the sauce being incorporated into the chicken and you'll have a better tasting dish.
So, Life is full of trade offs, nicer looking, or more flavor. Both are great in their own way.
1. Mix the flour mixture ingredients together in a large bowl and set aside.
Mix up the panko mixture ingredients in another large bowl, set aside.
For the milk mixture, place the eggs in a smaller bowl, and whisk until smooth. Add the milk and blacken and continue to whisk until it's all blended, set this aside also.
2. Cut off any extra fat that may be on the chicken, then slice the each breast in half horizontally.
3. Use one hand to dredge a breast in the flour, then the egg / milk mixture. Using the same hand, place it in the bread crumb mixture, pat down and carefully turn it over. Using your other hand, add more bread crumbs to both sides. Doing it this way, you'll keep one hand relatively clean.
Set these on a sheet pan while you're breading the rest of the chicken.
5. Pour about 1/4" of oil in a black frying pan, and heat to about 350 degrees. Place the chicken in and fry only until it's brown. Your not finish cooking it at this time, you'll be doing that in the oven.
6. As the chicken is browned, place them on a sheet pan. When all are browned, place the pan on a middle rack in the oven while you make the sauce.
7. Make the sauce by first placing a mixture of oil and butter in a saute pan set on medium high. Cut the onion into slices from the root end, place in the pan. Cut the red pepper into strips, and the serrano peppers into rounds, and place these in the fry pan as well. Add the wine and chicken broth, and turn the heat to high. Let this boil to reduce, and cook the vegetables until they're nice and soft. Finish by adding the sour cream, stir it in well, and let it get hot.
8. Serve immediately with mashed potatoes.
9. ABe sure to check out the leftover recipe for this dish. I didn't have enough sauce, so cleaned out the refrigerator and kicked it up for a very different flavored meal.