For the lemon pastry cream, in a medium saucepan over medium heat, add milk and lemon zest. Bring to a just a simmer. Remove from heat.
2 cups whole milk, 1 tablespoon lemon zest
In a medium mixing bowl, stir together sugar, cornstarch and salt. Whisk in egg yolks until mixture is pale yellow and fluffy, about 2 minutes. The mixture will be pretty thick.
115 grams sugar, 35 grams cornstarch, ¼ teaspoon kosher salt, Egg yolks from 5 large eggs
While whisking the yolk mixture, slowly pour in warm milk. Return the mixture back to the saucepan. Cook over medium heat, whisking constantly until thicken, about 3 minutes. Pause to check for bubbles. When it starts bubbling, whisk for 30 more seconds. Remove from heat. Whisk in butter until combined. Transfer to a large heatproof bowl. Cover with plastic wrap by pressing down to the surface of the pastry cream. Chill in the fridge for 2 hours or until cold.
2 tablespoons unsalted butter
For the strawberries, after cutting them, place them in a large bowl. If you want them to be sweeter (optional), toss them with sugar and cover with plastic wrap. Set aside in the fridge for about 30 minutes.
1½ pints fresh strawberries, 1½ tablespoons sugar
When the pastry cream is cold, start on the stabilized whipped cream. In a small microwave bowl, add water. Sprinkle the gelatin powder over evenly. Set aside to soften for 10 minutes. Microwave for 10 – 15 seconds. Stir to dissolve.
2 tablespoons drinking water, 1 teaspoon unflavored gelatin powder
In a large mixing bowl with an electric mixer fitted with a whisk attachment, add heavy cream and powdered sugar. Whisk for 1 minute at medium-high speed. Pour the warm gelatin liquid into the cream. Continue to whisk until soft peaks form. Cover and keep in the fridge until ready to use.
1 cup cold heavy cream, 3 tablespoons powdered sugar
To make lemon diplomat cream, in a large mixing bowl, add lemon pastry cream, whisk to smooth out. Whisk in 1/3 of the whipped cream to loosen the pastry cream. Then gently fold in half of the leftover whipped cream (not all) until blended.
To assemble, in a large piping bag fitted with a ½-inch piping tip, add diplomat cream. Pipe about ½ cup of cream into each serving bowl. Divide the strawberries into each bowl. Cut the palmiers in half and place 2 halves in each bowl. Serve immediately.
8 palmiers