If using dried beans, steep them overnight in water, first.
The following day, boil them in water for around 40-50 mins. Don't allow them to go completely soft as they'll continue to cook when you remove them from the heat.
If you are using tinned beans, drain the brine and then give them a good rinse to remove the flavour of the brine.
Add your beans to a large serving bowl.
Now add the onion, pepper and chopped parsley and mix together, carefully.
In a mug, mix your vinegar, oil and tahini then season with salt and pepper.
Do a taste test and add more tahini or more vinegar if you like.
Pour over your bean salad and mix together.
Now decorate your piyaz with your hard boiled eggs.
You can garnish with cherry tomato if you like.