Toast the bread and spread a generous amount of hummus on slice. Top with the grated carrot and cucumber.
Add the avocado slices in a fan-like layer and lightly season with some sea salt and freshly ground pepper. Spread a little more hummus on top of the avocado - this will ensure the alfafa sprouts will stay put. Add the final layer of alfafa sprouts.
Spread the other slice of toasted bread with the remainder of the hummus and place on top of the sandwich. Carefully cut diagonally - put a sharp knife in the centre of the sandwich, cut outwards on one side and then repeat on the other. (This way the ingredients won't spill out the sides.)