Chop the potatoes up into chunky cubes and cover with a wet paper towel. Microwave for about 4.5 - 5 minutes. You wont have to boil them if you do this!
Add a small dash of oil to the pot and sautee the onions until slightly translucent.
Add the coconut milk and red curry paste and stir until fully incorporated.
Add the water, soy sauce, sugar, and rice vinegar.
Add the salt, chili powder, and crushed red pepper.
Cook on a low heat for a few minutes.
Toss in the potatoes, green beans, and bell peppers.
Cover and cook on a simmer until green beans have softened and the potatoes can be pierced with a fork.
If your curry is too thin, then cook uncovered to let it evaporate. If it's too thick, add some water.
Add in the shrimp and serve over a bowl of rice!