Ofen vorheizen to 180°C and grease a muffin tray or line with paper cups.
In a bowl, mix dry ingredients: flour, baking powder, salt, mustard powder.
Stir in cheese and biltong (and onion/herbs if using).
In another bowl, whisk eggs, milk, and oil/butter.
Pour wet ingredients into dry ingredients and mix until just combined (don’t overmix).
Spoon batter into muffin cups (about ¾ full).
Backen für 20–25 minutes until golden and cooked through.
Cool slightly and enjoy warm.