Prepare the Reduction: In a saucepan, add water, white vinegar, and crushed white pepper. Let it reduce by 1/3.
Cool the Reduction: Once the reduction is ready, filter it and let it cool.
Prepare the Asparagus: Clean the asparagus and remove the hard part. Cook them in boiling salted water for about 5 minutes.
Grill the Asparagus: Season the asparagus with oil and salt, then brown them on a hot griddle.
Season the Beans: Season the beans with oil, salt, marjoram, and fennel.
Make the Hollandaise Sauce: In the saucepan with the reduction on very low heat, place the egg yolks and mix well, heating it without exceeding 60°C.
Add Butter to Hollandaise: Off the heat, add the butter a little at a time while mixing until smooth and shiny.
Finish the Hollandaise Sauce: Add lemon juice and salt to the hollandaise sauce, continuing to mix.
Plate the Dish: Plate the beans, asparagus, hollandaise sauce, toasted hazelnuts, and fresh herbs.