Preheat your oven to 250°F. Line two baking sheets with parchment paper.
Whip the egg whites with an electric mixer on medium speed for 1 minute. Gradually add the granulated sugar.
Once all the sugar is added, increase the speed to high and whip for 9 more minutes. Add food coloring around minute 8. (For a swirl effect, skip the food coloring here and see step 7 below.)
The meringue should be stiff, glossy, and shiny.
Gently fold in the cornstarch and lemon juice with a spatula until combined.
For a swirl effect, brush lines of gel food coloring inside a piping bag from the bottom to the top. Place the bag in a cup to keep it steady while brushing.
Transfer the meringue to two 16-inch piping bags fitted with open star tips.
Pipe 3 1/2-inch meringue nests on the baking sheets, leaving a small space in the center for filling.
Bake for 1 hour, then turn off the oven and leave the pavlovas inside for another 30 minutes. Let them cool completely before filling. Store unfilled pavlovas in an airtight container at room temperature for up to 5 days.