Line a plate with paper towels, arrange the shrimps in a single layer, place more paper towels on top and press lightly to remove as much surface moisture as possible.
If your cashew nuts are not toasted yet, do it now in an oil-free pan.
Peel and slice the onion.
Drain the thawed sweet peas.
In a small bowl, mix together all the ingredients for the sauce.
Heat the cooking oil in a wok or frying pan and saute the sliced onion for about half a minute.
Turn up the heat, add the shrimps, sprinkle in the salt and pepper, and stir fry for half a minute or just the until the shrimps change color.
Add the peas and cashew nuts, and stir fry for ten seconds.
Stir the sauce in the bowl (starch has a nasty way of settling at the bottom) and pour into the pan.
Stir fry for another half a minute or just until the sauce is clear and thick (the shrimps will be cooked through at this point.
Taste and adjust the seasonings, if needed, before serving your shrimp, peas and cashew stir fry.