Place the cut chicken pieces in a bowl and pour the 1 cup of dill pickle juice over them. Marinate in the refrigerator for 30 minutes to 4 hours.

In a shallow dish, whisk together the flour, panko breadcrumbs, paprika, garlic powder, onion powder, cayenne pepper, salt, and pepper.

Remove the chicken from the brine, letting excess drip off. Dredge the chicken in the flour mixture until fully coated. Let rest on a wire rack for 5 minutes.

In a small bowl, whisk together mayonnaise, sour cream, fresh dill, 1 tbsp pickle juice, and minced garlic to make the sauce. Refrigerate until ready to use.

Heat vegetable oil in a skillet over medium-high heat (350°F). Fry the chicken pieces in batches for 3-4 minutes per side until golden brown and cooked through (165°F internal temp). Drain on paper towels.

Warm the tortillas in a dry skillet for about 30 seconds per side.

Assemble the tacos by layering shredded lettuce, crispy chicken, pickle slices, a drizzle of dill sauce, and crispy fried onions on each tortilla. Serve immediately.