Clean and wash the laal saag leaves retaining the soft stems. Chop them roughly and keep aside.
Heat mustard oil to the smoking point and let it cool a bit. Add in cumin seeds, bay leaf, and red chillies. Allow to crackle.
Add in the chopped garlic and saute for a minute. Add the chopped onions. Saute until the onions are translucent.
Add in the potatoes. Mix well. Saute for a few minutes.
Now add in the dry masalas - salt, Kashmiri red chilli powder, coriander powder, and turmeric powder. Mix well.
Add a bit of water, cover with a lid and cook until the potatoes are almost done.
Now, add in the chopped laal saag leaves. Saute for 3-4 minutes. Cover with a lid and cook for a few minutes until the liquid dries up and the saag is done.
Finish with amchoor powder. Mix well. Check the salt and add more if required.
The Aloo Laal Saag (Red Amaranth) Sabji is ready to serve. Serve hot with chapatis or paranthas.