The same dressing behaves differently on beans and cucumber. Chickpeas can sit in it while you prepare the rest; cucumber starts giving up water and gradually dilutes the whole bowl.
Drain and rinse a 400 g tin of chickpeas. Toss with one tablespoon lemon juice, two tablespoons olive oil, a small pinch of salt, and black pepper. Add finely chopped red onion if you enjoy its raw bite.
Cut half a cucumber into small chunks. Add it shortly before serving with a handful of chopped parsley and a few halved cherry tomatoes. Taste the dressed chickpeas rather than just the liquid at the bottom: the beans should carry enough seasoning of their own.
This makes two light lunches with bread. For a packed version, keep cucumber and tomatoes in a separate compartment and mix when ready to eat. Keep the prepared meal chilled during storage and transport; a screw-top jar is convenient, but it does not make a salad shelf-stable.