Add 250 g plain flour, ¼ teaspoon baking powder, and Salt to a large mixing bowl. Gradually add 125 ml hot water, and knead until the dough is soft and pliant. Cover the bowl and rest for 30 minutes while you make the filling.
Make the paneer momo filling
Grate 200 g paneer into a large mixing bowl. Then grate 200 g cabbage, 1 small carrot, and ½ medium onion into the small bowl. Finely chop and add 2 green finger chillies.
Season with 1 teaspoon ginger garlic paste, ½ teaspoon salt, black pepper (to taste), and 1 tablespoon momo masala. Mix all the spices into the filling by massaging them in. Once thoroughly mixed, chop and add 2 spring onions, then stir through.
Cut out the momo wrappers
Take your momo wrapper dough and separate it into two pieces. Roll them both into balls. Lightly dust your work surface, and begin to roll one of the balls into a flat round. Once thin enough, use a small cookie cutter (or vati/kachori dish) to cut out your momo wrappers*. Once cut, lightly dust with 2 tablespoons cornflour. You can now store these in the refrigerator, freeze them, or use them straight away. If using straight away, no need to dust with cornflour.
Fold the momos
Lay out one of your momo wrappers on a flat surface. Place a small spoonful of paneer stuffing in the centre. Bring the sides into the centre and begin to pleat, taking a little more dough each time. Finish the pleating by pinching the dough together. Repeat with all remaining momo wrappers and filling.
Steam the momos
Add plenty of water to the bottom of your steamer** and set it on your stove at medium heat. Once the water comes to a rolling bowl, add your paneer momos to a steamer plate (grease this with oil beforehand if you wish, to help prevent sticking) and cook for 15 minutes, or until the momos are translucent.
Notes
*Alternatively, you can make twenty very small balls from your momo dough and roll out the wrappers individually. This can sometimes take longer. **I used an idli steamer, but a steamer plate, a proper dumpling steamer, or even a steamer basket can work. Depending on the type of steamer you use, you may have to line it with parchment paper, banana leaves, or a thin layer of neutral oil to prevent the momos from sticking.