Preheat your oven to 220ºC/430°F.
Line a baking tray with baking paper. Place the maple syrup in a bowl and coat each rasher of bacon in the syrup and lay them in the tray so that the don't overlap. Bake in the oven for 20-25 minutes, turning after 15 minutes. Keep an eye on the bacon to make sure it crisps but does not burn. Once cooked carefully remove the bacon onto a plate and pop in the fridge to harden.
Meanwhile, preheat a chargrill pan or BBQ plate. Butter the sourdough on both sides. Wash and shake dry the cos lettuce removing any brown or damaged outer leaves. Cut the cos lengthways in half and brush the cut side with a little olive oil.
Prepare your dressing by mixing all of the ingredients together well. I'm not overly fond of anchovies, but in this dressing, they just add a wonderful hit of saltiness and no fishiness at all. If you just can't bring yourself to use them, add some sea salt instead.
Once you grill is heated begin by charing the sourdough until toasted and then rub with the peeled clove of garlic. Cut into a wedge to serve. Next, char the cos for a minute, not to cook, rather impart a charred flavour.
Assemble by placing the cos on a plate charred side up. Drizzle over the dressing and top with the maple bacon, sourdough garlic crouton, shaved parmesan, parsley and grate the boiled egg over the top (optional). Serve with a sharp (even a steak) knife so it can be chopped up to combine all of these divine flavours.