You can use fresh or frozen skinless salmon fillets for this recipe, but ensure they are thoroughly defrosted if frozen. My fillets are roughly 6oz/170g each.
The daal will still be delicious if you can't find curry leaves, but they add great flavor. You can often find them in those plastic envelopes in the fresh herb section. Or look for bigger bags of them dried near the Indian section of the grocery store.
You can use chicken or vegetable broth for the daal. Both will add a lovely flavor. If you don't have broth, just use cold tap water, but you may need to add more salt at the end of cooking.
Also known as a Tadka, this is a sizzling flavored oil that's poured over the finished dish. It is an optional step, but totally worth it.
There isn't a large amount of marinade for the salmon. It is more of a spiced oil rub. You want to turn the salmon to coat it all in the spiced oil.