Mom's recipe that I tried for Tamil New Year's Day this year and it came out pretty tasty!
2 raw mangoes - cut into rectangular slivers, 1/3rd (of mango) the quantity of vellam (jaggery), curry leaves, 3 green chillies chopped, mustard seeds, grated ginger, gingelly oil, salt.
Add water to just cover the mango slivers and pressure cook for 5 whistles. In a pan add the cooked mango and water, melt the jaggery in it and keep stirring on high-heat for 5-10 minutes until the mixture thickens to a suitable consistency.
In a separate smaller pan,splutter mustard seeds in a few teaspoons of gingelly oil, add it to the mango-jaggery mix, add curry leaves, grated ginger and salt on top.
Some interesting tit-bits I picked up about manga-pachadi -- it's usually made on Tamil New Year's Day and it is supposed to have 5 tastes in it - sweet, pulipu (tangy), karam(spicy), kasapu(bitter -- from neem, in my case from karuvepila) and ginger taste (what is it called? Or perhaps from the salt) so your entire year is filled with these flavors. Cool stuff.