Savoury Crayfish Éclairs

Pastry

• 30 g Parmesan cheese, cut in pieces (2 cm)
• 80 g unsalted butter, diced
• 150 g water
• 2 pinches mustard powder
• 1 - 2 pinches cayenne pepper, to taste
• ¼ tsp fine sea salt
• 120 g plain flour
• 3 medium eggs

Assembly

• 240 g crayfish
• 110 g mayonnaise
• 1 lemon, finely grated zest and 25 g juice
• 1 ½ tsp Dijon mustard
• 2 pinches ground cayenne pepper
• 2 pinches fine sea salt
• 1 pinch ground black pepper
• 20 g rocket leaves