It's very simple. Peel the ginger, cut it into cubes (you can grate it).
Add soy sauce and lemon juice to the ginger. Marinate the shrimp in the resulting sauce for 30 minutes.
While the shrimps are being marinated, cut a quarter of the mango into thin slices.
Do the same with the avocado, after removing the skin from it. I sprinkle it with lemon juice so it doesn't darken. If you bought too hard avocado, it does not matter. It should be wrapped in newsprint and left at room temperature for 2 days. So it will ripen quickly.
Prepare the sauce. Mix vegetable oil with balsamic vinegar and mustard. Place the torn lettuce leaves, avocado slices, mango and shrimp on a platter or in a salad bowl. Garnish with red onion rings. Pour over the sauce.