PREPARING THE ÉCLAIRS:
In a saucepan, bring the milk, water, honey, salt, and butter to a boil.

Once boiling, add the flour all at once.

Stir to dry out the dough. In a mixer bowl with the paddle attachment, add the eggs one at a time.

To check if the dough is ready, run your finger through it—if the line closes up, it's ready.

Transfer the dough to a piping bag. On a baking sheet lined with parchment paper, pipe out the dough into éclair shapes.

Lightly brush them with a little water using a pastry brush, being careful not to flatten them.

Run a fork along the top to create ridges.

Bake at 350°F (180°C) for 35 minutes.

PREPARING THE BLACK CHERRY PURÉE:
In a saucepan, add 1 cup (150 g) frozen black cherries.

Add 1/4 cup (50 g) granulated sugar, bring to a boil, and then add a sheet of gelatin, or 1 tablespoon agar agar, or jam-setting sugar.

Blend with an immersion blender or regular blender, then strain through a fine mesh sieve.

Cover with plastic wrap directly on the surface and let cool at room temperature.

PREPARING THE PASTRY CREAM:
In a saucepan, heat the milk and add a pinch of salt.

In a mixer bowl, beat the egg yolks and sugar until pale.

Mix in the flour and cornstarch.

Gradually add the hot milk, mixing well, then return everything to the saucepan and cook over low heat, stirring constantly.

Cook until the cream thickens.

Remove from heat and stir in the butter and 1/4 cup (50 g) black cherry purée.

Cover with plastic wrap directly on the surface and let cool.

ASSEMBLY:
Take an éclair, turn it over, and make 3 holes in the bottom using a piping tip.

Carefully fill with the pastry cream so the éclair doesn't burst.

Spread the remaining cherry purée on top.

Sprinkle with chopped pistachios or any other topping you like.