Don't use packaged egg whites for this because you won't get the same volume and stability as you would with fresh egg whites. This dessert may be made a day in advance, but the caramel should be added a few hours before serving.
3 egg whites
2/3 cup sugar
1/2 teaspoon vinegar
½ teaspoon vanilla
2 cups milk
3 egg yolks
1/4 cup sugar
1 teaspoon vanilla
½ cup granulated sugar
¼ cup water
Beat egg whites with an electric beater until foamy. Slowly add sugar and beat until thickened. Beat in vinegar and vanilla. Beat until very thick and glossy.
Bring a skillet of water to simmer, turn heat to medium-low so water just bubbles gently. Use soup spoons to make egg-shaped quenelles of meringue and poach about 2 to 3 minutes per side in the water. Remove with a slotted spoon to a baking sheet lined with paper towel.
Heat milk until hot. Beat egg yolks and sugar until thickened. Slowly beat in hot milk. Return to milk pot and cook gently until mixture coats the back of a spoon. Add vanilla and cool. Refrigerate until needed.
Divide custard among 4 bowls and top each with two meringue "eggs."
Heat sugar and water in a heavy pot over high heat, swirling pan occasionally. Boil until sugar becomes a light caramel colour, about 8 minutes. Let cool slightly, about 2 minutes, then with the tines of a fork or a spoon drizzle caramel decoratively over eggs and custard.