4 quart-size plastic food storage bags
4 small, boneless, skinless chicken breasts
1 5-ounce bag of salted pretzels, any shape
1 tablespoon fresh thyme leaves, chopped
Salt and freshly ground black pepper
Vegetable oil, for frying
2 tablespoons butter
2 tablespoons flour
2 cups milk
3/4 pound, about 2 1/2 cups, sharp yellow cheddar cheese, shredded
2 heaping tablespoons spicy brown mustard
1/4 cup flat leaf parsley leaves, a generous handful, chopped
1/4 small yellow onion, finely chopped
1 large sour dill pickle, finely chopped
1 lemon, cut into wedges
Preheat a large non-stick skillet with a 1/4-inch of vegetable oil over medium-high heat. Sprinkle a little water into four medium food storage baggies. Place 1 chicken breast in each bag and seal it up, pushing out excess air. Use the bottom of a heavy pot or pan and pound each breast until flat, just shy of busting out of the bag. Repeat with the other 3 chicken breasts.
Place the pretzels in a food processor or blender and grind until fine. Transfer the ground pretzels to a shallow dish, add the thyme and some salt and pepper. Crack and beat 2 eggs in a second shallow dish with a splash of water. One at a time, coat each chicken breast in the egg and then the ground pretzels.
Add the pretzel-coated chicken breast to the hot oil. Cook in a single layer, in 2 batches if necessary, about 3 or 4 minutes on each side, until the juices run clear and breading is evenly browned. While the chicken is frying, in a medium saucepot over medium heat, melt the butter and add the flour to it. Cook flour and butter for 1 minute and then whisk in the milk. When the milk comes to a bubble, stir in the cheese and mustard with a wooden spoon. Season with a little salt and pepper, and remove cheese sauce from the heat. Transfer the fried pretzel-crusted chicken breast to a serving plate, drizzle with the mustard cheddar sauce, then sprinkle with a little parsley, finely chopped onion and sour dill pickle. Serve lemon wedges alongside.