Prepare lobster by removing head and rinse out remaining tomalley. Rinse the neck meat gently under running water, removing any tomalley, and pat dry with paper towel

Cover meat tightly with cling film to prevent discolouration and refrigerate until needed.

Bring 2.5 litres of water to the boil in a stockpot, add lobster heads and fish heads. Reduce heat to low and simmer until reduced by half (2 - 3 hours).
Strain, discarding solids and set aside.

For the roux, heat vegetable oil over low-medium heat in a large casserole or heavy-based saucepan. Add flour and stir frequently with a wooden spoon until mixture starts to deepen in colour (15 - 20 minutes).

Reduce heat to very low and stir continuously until roux is dark brown in colour and smells nutty (an additional 10 - 15 minutes; be careful, the mixture can quickly burn if left unattended).

Add onions, celery, capsicum, garlic, sausage and bay leaves. Stir occasionally until vegetables start to soften (10 minutes).

Gradually add the lobster stock, stirring continuously to create a thick soup. Add enough stock for your desired consistency.

Season to taste with Worcestershire, cayenne and sea salt flakes.

Meanwhile, prepare lobster tails by splitting lobsters in half lengthways, using scissors to snip through the soft underside then finishing with a sharp knife to slice through the flesh and harder outer shell. Remove the digestive tract.