Preheat the oven to 200°C (400°F). Pour the vegetable oil into a roasting tin or large oven-safe baking tray and place it in the oven to heat while you prepare the chicken.
Crack the eggs into a shallow bowl and whisk together with half of the salt (about 1/4 teaspoon).
Place the flour in a second shallow bowl and mix in the remaining salt, mustard powder, and paprika.
Place the crushed pretzels in a third shallow bowl and stir in the onion flakes to combine.
Working with one piece of chicken at a time, dredge it in the seasoned flour, then dip into the beaten egg, and finally press into the crushed pretzel mixture until evenly coated. Use one hand for wet and one for dry if needed to avoid sticky hands.
Place each coated chicken finger on a lined baking tray. Repeat until all chicken is coated.
Carefully remove the preheated roasting tin from the oven and place the lined tray (or place the chicken directly in the hot tin if using it) into the oven. Bake for 8 minutes, then use tongs to flip each piece and bake for another 8 minutes, until the chicken is cooked through and the coating is golden and crisp.
Check an internal piece of chicken reaches no pink in the center and juices run clear, then serve with your choice of dipping sauce or sides.
