Dry roast pepper(milagu), cumin seeds(jeeragam), carom seeds/ajwain(omam) and coriander seeds(malli) in low flame for 2-3 mins or just hot to touch. Then add dry ginger(sukku) powder.
Fry for 30 seconds and switch off the stove. Once cooled, grind in mixie to fine powder.
Take jaggery, add water and boil till jaggery completely dissolves in water.
Filter the jaggery syrup to a pan, switch on the stove in medium flame and add the ground powder to the syrup.
Keep stirring continuously until it thickens like honey.
Add gingelly oil/Nallennai and switch off within a minute or 2 when it passes one of the below tests. Once switched off, immediately transfer to a tiffin box. Keep opened until completely cooled down. Then, close it air-tight and use till Christmas(if you do in large quantity) !! Tests are:
Diwali legiyam becomes glossy/shiny.
Diwali legiyam doesn't stick to hand when touched with wet hand.
Diwali legiyam starts leaving the pan
Notes
1.Do not boil after the legiyam becomes glossy. Else it will become chewy rather than being smooth like ladoo. 2.If cooked more till oil separates, it will become like chewy kamarkat or stony kalkona!! If it becomes hard, make balls and store, else it will become a tug of war to take the legiyam out of the stored container ;) 3.If you need this to be more sweet, increase jaggery or just dip it in honey while eating. 4.Original recipe includes more items like kandandhipili, arisi thipili and others from herbal medical shop(naatu marundhu kadai). But, the 5 items mentioned in this post are readily available and commonly used ingredients.
Recipe by My Healthy Kiddo at https://www.myhealthykiddo.com/diwali-legiyam-deepavali-marundhu-recipe/