In a heavy bottom pan, heat mustard oil. Once the oil starts smoking, add cumin seeds, mustard seeds, fennel seeds, methi dana, asafoetida, and dry red chilli. Fry till seeds start spluttering.
Add pumpkin along with the salt, turmeric powder, red chilli powder, coriander powder, and salt. Stir to combine.
Cover and cook the pumpkin cubes over low heat for 20 - 25 minutes or till pumpkin is tender. Stir occasionally in between.
Once the pumpkin turns soft, add jaggery powder, mango powder, and kasuri methi. Stir to combine.
Let the pumpkin pieces cook over low heat for next 5 minutes. Stir occasionally in between.
Serve Kaddu Ki Sabzi warm with poori.