Recipe on internet for home made Ranch Dressing which keeps for months, you make the dry seasoning then add mayonnaise later to get the dressing.
In a pestle and mortar mix the following:-
2 tbsp dry parsley
1 tsp dill
2 tsp garlic powder
3 tsp onion powder
1/2 tsp black pepper
1/4 tsp salt
1/2 tsp paprika
1/4 tsp cayenne
To make the dressing use 1 tbsp of the above with
4 tbsp yogurt
2 tbsp mayonnaise
2 tsp lemon juice
1 tbsp milk or as much as you need to make it runny
I used the yogurt and lemon juice as I could not get buttermilk
Also seen a recipe that has 2 tsp dried thyme in the Ranch Dressing and you just mix dry ingredients with greek yogurt