Prepare the meringues:

• Preheat oven to 225°F. Line two baking sheets with parchment paper.
• In the bowl of a stand mixer fitted with the whisk attachment, on medium speed, whip egg whites and cream of tartar until whites begin to foam. Slowly add sugar, ¼ cup at a time. Whip on high speed until stiff peaks form. When a bit of egg white is placed on a baking sheet, it should remain stiff and precisely in place and not spread at all.
• Using a spoon, place a dollop of meringue on the sheet pan, spacing them out so that you fit 6 on a sheet pan. Don't worry about going close, meringue doesn't spread while baking.
• Using the spoon, create a well in each nest. Use your spoon and get creative (see images) and don't worry about it being perfect. Perfect isnt pretty in this case. The more movement the better. Bake meringues for 1 ½ hours and then turn the oven off. Let dry overnight if possible. At this point meringues can be frozen. Be aware that they will break if not stored properly, so allow ample room in the container and do not overcrowd.
• Prepare the lemon curd: In a medium-sized saucepan, combine sugar, cornstarch, and salt. Whisk to combine. Add lemon juice and margarine; place pan over medium heat. Once margarine has melted, bring to a simmer, whisking constantly. Make sure no lumps are left.
• Place egg and yolks into a small bowl. Beat with a fork until combined. Remove about ¼ cup of lemon mixture from the pot and add to the eggs. Mix vigorously and quickly to prevent curdling. Add egg mixture to the pot; stir together, whisking constantly, over low heat. After 3-5 minutes, you will notice the curd thickening. Make sure curd does not reach a boil; keep at only a low simmer. Once curd has thickened, stir in the lemon zest; remove from heat.
• Transfer curd to a bowl; cover with plastic wrap. Press plastic down gently so it adheres to the entire surface. This will prevent a thick crust from developing. Let cool at room temperature for 2 hours.
• In the bowl of a stand mixer fitted with the whisk attachment, whip the non-dairy whipped topping until stiff peaks form. Using a spatula, fold together with the lemon curd, starting with about ½ cup of whipped topping. Taste; add more topping to taste (some like the cream more tart, some more sweet). Once you achieve the desired flavor, transfer to a tight-lidded container; refrigerate until ready to use.Curd can be prepared up to 3 days in advance of using. Curd cannot be frozen.
• To assemble: Gently place each pavlova/meringue on a dessert plate. Top with a generous spoonful of lemon curd. Top with berries and decorate with mint leaves. Repeat. Serve immediately.