Method
For the cod, pre-heat oven to 180C.
Place cod fillets on a baking tray lined with baking paper.
In a separate bowl bring together breadcrumbs, juice, and zest of 1 lemon, olive oil and parsley until the breadcrumbs come together.
Pat the crumb mixture with a little pressure onto the fillets with your fingertips.
Bake cod for 20 minutes.
As the cod cooks prepare your Beurre Blanc sauce.
For the Beurre Blanc, heat 10g of the butter in a small pot over medium heat and sweat off shallots until translucent.
Add in white wine and white wine vinegar and reduce for 10 minutes until half the amount of liquid remains.
Strain the liquid over a new pot and place on low heat.
Add the chilled butter one piece at a time, whisking constantly, ensuring each piece has melted before adding another.
Continue to add the butter, whisking vigorously each time and keeping the temperature low until a creamy sauce forms. The process can take about 20 minutes. If your sauce looks like it is separating, remove from the heat and whisk until it comes together again before placing back on the hob.