First rinse and finely chop the veggies in a food chopper or a food processor or with a knife. If you want you can blanch the cabbage before chopping it. If blanching then remember to drain all the water very well.
In a bowl add the chopped veggies and steamed corn kernels. You can skip corn if you want.
Then add mayonnaise, black pepper powder, a pinch of salt and sugar.
Add sugar and black pepper powder as required.
Then add lemon juice for a tang. If you want, you can also add some red chili flakes or some dried herbs like oregano, thyme, basil.
Mix everything very well. Check the taste and add some more salt, sugar or black pepper if required.
Take the bread slices and spread some butter on them. This is an optional step.
Now spread veg mayonnaise stuffing on the bread slices.
Place on top the remaining buttered slices and slice the sandwiches.
Serve coleslaw sandwiches plain or accompanied with some french fries or potato wedges or dips like mayo dip, cheese dip or tomato ketchup.
Notes
If you prefer then you can blanch the cabbage leaves before using them. Then drain all the water and finely chop them.
The recipe can be scaled easily. Make a big batch for pot lucks and get-togethers.
Use your preferred mayonnaise.
You can add your choice of herbs or spices to make these sandwiches more flavorful.
Salad veggies like carrots, bell pepper, steamed green peas, steamed corn, boiled potatoes, cabbage, steamed or blanched french beans and herbs like celery, parsley, cilantro or mint can be used in the coleslaw stuffing. This will make the sandwiches more healthy and filling.
Note that if you use watery veggies like cucumber or beets then don't refrigerate the sandwiches. Eat them as soon as they are made.