Prep the veg - Slice or grate the ginger and turmeric, without removing the skin. Fill a glass jar with the veg.
Prep the marinade - Heat some oil in the pan and add the spices. When the mustard seeds start to pop, turn the burner off and let cook slightly. Stir the oil/spice mixture into the ginger and turmeric in the jar.
Finish - Once the mixture has cooled completely, add the salt and lemon juice. Store in the fridge for up to 3 months.