Hi CurrySwede,
Sorry that this didn't turn out for you.
The tablespoons should have been level, not heaped, I just went and measured it out in terms of 5ml teaspoons, and 1 level tablespoon is 3x5ml tsp, so all up it is 30ml salt for the recipe.
Now, the other thing is the size of the onions, we didn't weigh them here, but they were very large, and I would be guessing was approx 1kg of onion.
The resultant paste when cooked down made enough for about 15 portions of curries, so 30ml divided by 15 is 2ml which is about 0.5 tsp salt per curry. As no further salt is used in any of the recipes then it should be ok, and should be further diluted with the other ingredients. In comparison to other bases and recipes that level of salt is similar.
I've used the pastes for the last 4 months and haven't had any problems with them in regards to saltiness for everything from Beef Madras, to Paneer Tikka Masala and many others.
Unfortunately it appears the visual that I know having watched it might not have come through correctly in the explanation of the recipe details.
Again, I'm sorry it didn't work out for you.
Mark