Carefully pick the lobster meat from the shells, feeling the firm, briny flesh between your fingers. Set aside in a bowl, ensuring all the juices and bits of shell are removed for a clean, tender filling.
Slice the brioche buns in half horizontally, then melt butter in a skillet or toaster and generously toast the cut sides until golden brown and slightly crispy. Keep a close eye to prevent burning, and press them down gently for an even toast.
In a small bowl, whisk together mayonnaise, freshly squeezed lemon juice, chopped herbs, and a pinch of salt. This bright, flavorful dressing will bring the lobster filling to life.
Add the lobster meat to the bowl with the dressing, gently folding to coat each piece thoroughly. The mixture should be creamy, with the lobster remaining chunky and tender.
Once the buns are toasted, remove them from the heat and spread a little butter onto the cut sides if desired. Spoon generous amounts of the lobster mixture into each bun, pressing down slightly to pack it in.
Finish by squeezing a little extra lemon juice over the filled buns and sprinkling with additional chopped herbs for a fresh, colorful touch. Serve immediately while the bun is warm and the lobster is juicy.
