Peel and thinly slice cucumbers. You may choose to keep the peel on or partially peel. Peel the potato and thinly slice.
Apply up to 1 tablespoon of chutney (more or less depending on the spice level on one side of the bread.
Take one sliced and start layering veggies over the chutney side. Start with steamed veggies that do not release too much water like potatoes/beets as it will help the bread from getting soggy. Then layer over cucumbers and tomatoes. Finally layer onions/bell peppers making sure you have a nice flat layer of veggies.
Sprinkle with chat masala or salt & pepper (optional). Finally place the second slice of bread chutney side down over the veggies. Cut the sandwich in half lengthwise or diagonally and serve immediately.