Steam cook or microwave the mixed vegetables at 100% for about 4 minutes, till theyu2019re just cooked and still firm. Mash the yellow lentil well and keep both aside.
In a pan, heat the oil and add the cumin, aniseed/ saunf (if using) and fenugreek seeds. Stir a couple of times and add the asafetida powder. Stir once (do not allow to burn) and add the ginger julienne and sliced onion. Sautxe9 till the onion is soft.
Add the steamed vegetables and the mashed lentils. Add a cup (or a little more if you think you need to) of water, the turmeric powder, green chillies, tomatoes (if using, I didnu2019t) and the salt. Mix well and bring to a boil. Then simmer the mixture for about 5 minutes till the vegetable-lentil mixture is well blended and a bit thick in consistency. If you are using jaggery, then add it at this point.
Take the dal off the heat. Add the lemon juice, mix well and garnish with the chopped coriander. Serve warm with chappathis, parathas, naan or rice.