Preheat oven to 375F. Line a baking sheet with parchment paper or a silicon baking mat.
In a large bowl, combine the bread mix, cheese, water, mustard, 2 eggs, oil and ham. Dump the mixture onto a clean work surface and knead until the dough is smooth.
Divide the mixture into 20 equal sized balls. Place the balls on the prepared baking sheet.
Whisk the remaining egg with 1 Tbsp water. Brush the balls with the egg mixture. Combine the salt and dried onion and sprinkle on top of the balls.
Bake for 18 – 20 minutes or until golden brown. Serve immediately.