1 live rock lobsters (about 1kg)
Lemon wedges and herbs to serve
1 onion, finely diced
1 garlic clove, chopped
100g butter, coarsely chopped
⅓ cup plain flour
2 cups milk
1 tbsp dijon mustard
50g Gruyère, coarsely grated
50g parmesan, coarsely grated
¼ cup chives, chopped
¼ cup parsley, chopped
¼ cup dill, chopped
Preheat oven to 180C.
For mornay sauce, heat butter in a saucepan over medium-high heat and sweat the onion and garlic until softened. Add flour and stir continuously until flour begins to turn sand-coloured, for another 2-3 minutes. Gradually add milk, stirring well between each addition, until incorporated and sauce is smooth. Stir in the mustard and cheese, season well to taste and stir in herbs.
Bring a very large saucepan of salted water to the boil. Boil lobsters until half-cooked (4 minutes). Drain, then using a sharp knife and kitchen scissors, split lobsters in half. Remove meat from tails and legs (leave head and tail shell intact), coarsely chop tail meat and transfer to a bowl. Set shells and meat aside separately until required.
Combine half the mornay sauce with the lobster meat and stir to combine, then spoon mixture into shells in a baking dish, spoon extra sauce over to cover well, then bake in the oven until mornay turns golden and bubbly (20-30 minutes).
Season to taste and serve hot with lemon wedges and a leaf salad.