Canned palm hearts can be eaten straight from the tin or used in stir fries and they add a real crunch to summer salads.
Remove the outer leaves of the lettuce and cut each heart into quarters from top to bottom. Soak in a sink filled with cold water for a few minutes. Split the avocados and remove the stones. Scoop the flesh out with a spoon and chop into large chunks. Cut the palm hearts into chunks of the same size. Using a sharp knife, cut the cheese into small pieces. Whisk together the dressing ingredients with some salt and pepper.
Drain the lettuce, then tear into bite-sized pieces and divide between four bowls. Pile a quarter of each of the other ingredients on top of each serving. Pass round the dressing and let everyone toss their own salad.