Spread green chutney thinly on the inner side of two parathas. Add tamarind chutney sparingly if using.
On one paratha, layer cucumber, onion, and cheese if using. Top with the second paratha, chutney side down, to close each sandwich.
Grill
Heat a tawa or skillet on medium. Melt half the butter and add one sandwich.
Cook 2–3 minutes until the underside is golden and crisp; press gently with a spatula.
Flip, add more butter if needed, and cook 2–3 minutes until the second side is crisp and cheese melts.
Repeat with the remaining sandwich. Sprinkle chaat masala on top while hot. Serve warm.
Notes
Pat cucumber dry to avoid a soggy sandwich.Use a thin layer of chutney on one side for the cleanest bite.Cool slightly before packing for a lunchbox so steam does not soften the crust.Reheat leftovers in a dry pan rather than the microwave for best texture.Jain option: skip onion; use a cumin-yogurt spread instead of garlic-forward chutney if needed.