Tadka Dal #2

400g red split lentils/masoor daal
1.5l boiling water
2-3 tbsp blended tomato
1/4 tsp garam masala
2 hpd tsp ground coriander
1 tsp salt or to taste
2 tsp my red chilli mix
10-15 stems of coriander

For the Tadka:

1 small onion diced
4 cloves grated garlic
1 thumb sliced ginger
Sliced red or green chillies
1 tsp cumin seeds
75g Butter for cooking