Using your fingers, carefully pick through the crab and discard any bits of shell or hard cartilage. Try to leave the lumps as intact as possible. Put the meat in a large bowl.

In a medium bowl, whisk together the mayonnaise, chili sauce, bell pepper, lemon juice, 1/2 teaspoon salt, scallion, a couple dashes Worcestershire, and hot sauce. Season the dressing with pepper to taste.

Gently fold about 1/4 cup of the dressing into the crab with a rubber spatula, taking care not to break the crab into smaller pieces. Put the crab salad and the dressing in the refrigerator until cold.

Meanwhile, put the hard-boiled egg in a fine sieve set over a bowl. Using the back of a spoon, rub the egg through the mesh to make a fine-textured garnish. Set aside.

Divide the lettuce leaves among 4 plates. Top each with a tomato slice, and season with salt and pepper to taste. Place an avocado quarter across each tomato slice and top with 1/4 of the crab mixture. Spoon some of the dressing over the crab and sprinkle each salad with some of the egg. Serve and pass the remaining dressing at the table.