The original recipe called for 6 cups of diced yellow squash and zucchini. The recipe didn't say if that was raw or cooked, but after mixing all the ingredients together, the mixture looked like it needed a bit more squash. So I cooked and added in 1 more cup and changed the recipe to 7 cups of squash.
The recipe indicates you should saute the onion in butter. I noticed another recipe that I've used for many years calls for adding softened butter to the recipe, so I am guessing that the 4 tbsp of butter in this recipe isn't used just for sautéing the onion, but actually goes into the recipe. That's the way I made it.