Toast the bread, butter it lightly. Peel the avocado in half lengthways and twist the halves from the core. Cut the pulp into slices, drizzle with lemon juice and place on the toast slices. Salt and pepper.
Cut the tomato into slices and also place on the toast. Cut the spring onions into fine rings and sprinkle over them. Place the cheese slices on top and bake on grill for approx. 5 minutes.