In a stand mixer, add egg whites and beat them until soft peaks form.
Then, start adding sugar and cornstarch gradually while the mixer is still running.
Add vanilla extract, lemon juice.
Continue beating until stiff peaks form. This can take 8-10 minutes and the batter will be very smooth and glossy. Test it by rubbing mixture between 2 fingers. It should not be gritty.
Fill a piping bag with this mixture and attach Wilton's Tip 1M (big star tip).
Pipe meringue nests that are about 3 inches in diameter on a large baking tray, lined with parchment paper.
Use a spoon to indent the center slightly. This will create space for filling later.
Bake at 225 degrees F for 1 hr and 15 minutes. Do not open the oven during this time period!
When the baking time is over, turn off the oven but DON'T open the door.
Let it cool in the oven and dry out further for about 30 minutes.
Finally, remove tray from oven and allow these meringues to cool to room temperature.
Place the mini meringues on individual serving dishes.
Fill with whipped cream, top with fresh berries, drizzle slightly warm strawberry jam on top.
Serve immediately and enjoy.