Preheat the oven to 200°C (400°F). Pour the 3 tablespoons of vegetable oil into a roasting tin or baking tray and place it in the oven to heat while you prepare the chicken.
Crack the 2 eggs into a shallow bowl and whisk with half of the salt (about 1/4 teaspoon).
Put the 1/2 cup flour into a second shallow bowl and season with the remaining 1/4 teaspoon salt, the 1/2 teaspoon mustard powder, and the 1/2 teaspoon paprika; mix to combine.
Place the 1 1/2 cups crushed pretzels and 1 tablespoon onion flakes in a third shallow bowl and stir together.
One at a time, dredge each chicken tender in the seasoned flour, shake off excess, dip into the beaten egg (use one hand for wet and one for dry if desired), then press into the pretzel mixture to coat completely.
Arrange the coated chicken pieces on baking paper or a lined baking tray (or directly in the preheated oiled roasting tin) in a single layer.
Bake in the preheated oven for 8 minutes, use tongs to flip each piece, then bake for another 8 minutes until the chicken is cooked through and the coating is golden and crisp.
Check an internal piece to ensure it's cooked through, then serve with your preferred dipping sauce or sides.