The size of parchment paper required depends on what you would like to put in the prepared paper bag. It is better to start with a parchment paper that is at least 15 inches wide and 17 inches long. Folding the paper half will give you an idea of where to place food. You should leave 1 inch space to the left of fold to keep the fillet in center of the pouch you are going to fold. Put whatever seasoning and spices you like over the fillet along with any vegetables you want and get ready to lock everything inside the pouch you are going to prepare. The folding technique should no longer haunt you now as you get an easy way of doing it. Beat an egg and then get a pastry brush in hand to brush it around the three edges of parchment paper. This will seal the piquancy of food you are preparing and ease your cooking life. Now fold the paper to cover whatever filling is inside the packet. This folded packet will look like a simple rectangular wrap but you cannot stop over here as there is more folding to be done ahead. More folds are needed to keep the packet shut until the fillet and ingredients are fully cooked. Don’t panic as we have the easy folding method for you to start with. Make a triangular fold starting at one end of the packet and push it down. Make another fold overlapping the previously made triangular fold half way through. Continue making pleats along the side you started with. Basically, you are working around the edges of food to lock the food inside. You can make larger pleats as you move along the long side of the packet and shorter ones as you get closer to the end.  Make the last fold and tuck it under the half moon shaped packet very tightly. And you are all set to place the prepared parchment paper packet onto the baking sheet. There is another way of folding up the parchment paper that requires a bit of cutting and folding. Fold the paper in half and cut it into a heart shape. Now start making folds using the same technique explained above. This method might end up in a smaller parchment paper bag as you had initially cut the paper into a heart but both serve the same purpose and are super easy to seal your food tightly within.