Tear the bread, including crusts, into large coarse pieces and place in the bowl of a large food processor.
Process for 30 seconds - 1 minute or until fine crumbs form
Transfer to a large bowl. Stir in the parmesan and quinoa
Cook the sweet potato in a large saucepan of water for 12-15 minutes or until tender.
Drain and mash well. Set aside for 10 minutes to cool slightly
Add the tuna (be sure it is drained well)and shallot to the saucepan
Season with salt and pepper and mix until well combined
Shape 1/4 cupfuls of the mixture into 12 patties
Spread the flour over a large dinner plate
Beat the eggs in a shallow bowl.
Spread the bread crumb mixture over a large dinner plate
Press 1 patty gently into the flour, then into the egg followed by the bread crumb to coat completely.
Place on a tray or large plate
Repeat with the remaining patties
Place in the fridge for 30 minutes to chill (or if time doesn't allow, at least 10 minutes - this helps them to keep their shape)
Heat the oil in a large non-stick frying pan over medium heat (you know the oil is ready when a bread crumb added to the oil sizzles immediately)
Cook the patties in batches of 4-6 for 2-3 minutes each side or until golden. Transfer to a plate lined with paper towel to drain.
To freeze cooked cakes: Allow cooked cakes to cool completely at room temperature before wrapping in lots of 2 in a single layer(that means not stacked) in plastic wrap. Freeze for up to 3 months. Thaw in the fridge overnight and reheat in a warm oven, a frying pan over medium heat or in the microwave.
To freeze uncooked cakes: Wrap cakes in lots of 2 in a single layer in plastic wrap. Freeze for up to 3 months. Thaw in the fridge overnight and continue from step cooking the patties.