First thing is to make the 'glue' so in a small bowl or cup, mix together the cornstarch and water, set this aside but keep it handy, this is used to seal the rolls.
Open the package of spring roll sheets. Carefully pull off one sheet and place smooth side down on a clean counter with one corner of the sheet facing you. Very important, place a damp towel on the unused sheets, if the sheets dry out they are hard to pull apart and will tear.
Place a tablespoon or so of filling near the corner closest to you.
Fold the bottom (the corner closest to you) up over the filling.
Tightly roll, the filling will spread some, that is fine. When the roll is in the widest part of the pastry (left and right corners will be on the sides of the roll) fold each side towards the center. The roll should be about 5 inches long, and should look like an envelope.
Continue to roll, and when there is just a pointy section at the end away from you, use your finger and apply some of the cornstarch slurry you made just a few minutes ago to the edges of the pointy section (just like sealing an envelope), continue to roll and seal the edge, and just pat that seam down with your fingers. There, you just made a spring roll.
Repeat until you have either used all the filling or all the pastry sheets. 13 more to go.
To fry these, heat about 1 inch of oil in a pot. When hot, add 4-5 spring rolls at a time and fry, turn often, until golden brown, These cook fast so keep an eye on them. Remove to paper towels to drain and fry the remaining rolls. Perfect color.
Let cool for a few minutes then serve hot as is or serve with a dipping sauce of your choice. My Sweet & Sour Sauce is listed as a shortcut in the Recipe Notes section.