Step 1: Dry Roast fenugreek seeds in a frying pan and dry grind them coarsely and keep it aside.
Step 2: Heat oil in a pan, and add the mustard seeds, red chillies and hing . Keep aside to cool slightly.(I f you add hot oil to chilli powder it will burn it and discolour).
Step 3: To the ground fenugreek add the chilli powder and salt and turmeric mix well. Add the warmed oil to the fenugreek mixture and mix well. Leave to cool.
Step 4: Transfer the achar masala to sterelised jar and use as required. (Achar masala should be dry and crumbly extra oil is added as required when making the pickle).