Yachaejeon – Korean vegetable pancake

For the pancake

1 onion (90 g) 1 small zucchini (90 g) 4 spring onions ½ sweet potato (50 g) 1 green pepper 1 mushroom 1 g flour (¾ cup) 180 ml cold water (¾ cup) ½ tsp salt 4 tbsp olive oil

For the sauce

1 tbsp soy sauce 2 tsp white vinegar 1 tsp chili flakes 1 tsp toasted sesame seeds 1 tsp honey (optional)