Turn on the oven, 180°C or Gas Mark 4.
Juice and zest the lemon and place in to a dish. Crush the garlic cloves and mix in to the lemon juice and zest.
Wash the asparagus in cold water. Hold the asparagus lengthways; find the natural ‘snapping’ point, the fresher the asparagus the closer to the tip it will be. This ‘snaps’ off the woody end of the asparagus spear, usually a couple of centimetres, leaving the tender stalk and tip.
Wash and chop the shallots roughly.
Wash the tomatoes but leave whole.
Measure out four equal sheets of tin foil, large enough to wrap the fish fillets and veg.
Place a barramundi fillet and three prawns in each sheet and sprinkle with a tsp of olive oil.
Spoon the lemon and garlic mixture over the four fillets
Divide the asparagus, tomatoes and shallots between the four parcels.
Season with salt and pepper, and a sprinkle of parsley.
Fold the edges in on each foil parcel, being careful to not tear the foil or have gaps where steam or juices can escape.
Bake in the oven on a baking sheet for 20 to 25 minutes.
Once cooked, place each parcel on a plate and serve.