Every Indian family has its own dal, and most of them are good. What separates a memorable dal tadka from an ordinary one is almost never the lentils. It is the tadka: the spices bloomed in hot ghee and poured over at the last minute. Get the heat and the order right and the kitchen smells like a dhaba. Get them wrong and you taste burnt cumin for the rest of the meal.

For the dal

¾ cup toor dal (or half toor, half masoor)
3 cups water
½ tsp turmeric
1 tsp salt, or to taste
1 small tomato, chopped

For the tadka

2 tbsp ghee
1 tsp cumin seeds
¼ tsp hing (asafoetida)
2 dried red chillies, broken in half
4 cloves garlic, thinly sliced
1 small onion, finely chopped
1 green chilli, slit
½ tsp Kashmiri red chilli powder
A handful of chopped coriander
A squeeze of lemon

Method

Cook the dal. Rinse the dal three or four times. Pressure cook with water, turmeric and tomato for 4 to 5 whistles, until completely soft. Let the pressure drop on its own.
Whisk and season. Open the cooker and whisk the dal until smooth but not pasty. Add salt. If it is too thick, add hot water; dal thickens as it stands, so aim slightly looser than you want to serve it. Keep it at a gentle simmer.
Heat the ghee. In a small pan, heat the ghee on medium until it shimmers and a single cumin seed dropped in sizzles immediately.
Cumin and chillies. Add the cumin seeds and dried chillies. Let the cumin crackle and darken by a shade, about 15 seconds.
Hing. Add the hing and stir once. It needs only a few seconds; it scorches quickly.
Garlic and onion. Add the garlic first, then the onion and green chilli. Fry until the garlic is golden and the onion softens and colours at the edges, 3 to 4 minutes.
Chilli powder, off the heat. Turn off the flame, then add the chilli powder. The residual heat is enough to bloom it without turning it bitter, and it gives the ghee a brick-red colour.
Pour. Pour the tadka straight into the simmering dal. It should hiss. Stir once, add coriander and lemon, and serve.

The three mistakes we see most

Cold ghee. If the cumin just sits there, the ghee is not hot enough, and the seeds will stew rather than crackle. Wait for the shimmer.

Chilli powder on a live flame. Ground spices burn in seconds in hot fat. Always take the pan off the heat first.

Tempering too early. Tadka loses its aroma if the dal sits for half an hour after it goes in. Do it just before you eat. If people are running late, keep the dal warm and make the tadka when they sit down.

Why ghee and not oil

You can temper in oil, and plenty of regional dals do. But ghee is what gives dal tadka its signature smell, because fat-soluble aroma compounds in the spices dissolve into it and the ghee's own nutty notes join them. With a flavourful bilona ghee, two tablespoons is enough for a pot that serves four.

A second tadka, if you are feeling generous

Dhabas often do a double tadka: the full tempering above goes into the dal in the kitchen, and a teaspoon of ghee heated with a pinch of chilli powder and a few cumin seeds is drizzled over each bowl at the table. It is theatre, but it is very good theatre.

For a dal this simple we reach for our Desi Cow A2 Ghee. It has plenty of aroma for everyday cooking, and a 1 litre jar lasts a family through a lot of dal.