How much basil paste in a tube do I need to equal 1 cup of basil that you measure first and then chop?
I suppose the question here would be to ask what the recipe is for. I'm going to assume you're using it for something like a pesto or to be used in a cooked dish. I would just add it to taste.
Yes indeed. It would help to know the recipe. Basil paste could be used in pesto (the word means "paste" anyway, or anything that's been pounded in a morter). But for something like a panzanella it won't work at all. Or if it works it will work badly.
I'm sooty I didn't say what the recipe was. It's pasta alla amatreciana. No pesto. It's just supposed to have fresh parsley which I have and fresh basil which I can't find.
Bucatini al'Amatriciana---at least the authentic Roman version---doesn't require basil or parsley at all. Its essential components are tomato, onion, guanciale (or pancetta, some hot pepper flake and pecorino cheese. A little parsley couldn't hurt
but it's absolutely inessential. This is reading like one of those wierd, English adaptations that people like Jamie Oliver come up with.
Now dust off the soot and get back in the kitchen.
Does the basil paste have garlic and olive oil in it? If so I might just omit it, since you're probably putting those ingredients in anyway. I make pasta alla amatriciana all the time in the winter, and don't use basil at all - I put a little hot red pepper in instead.
And if it doesn't have extra ingredients, just basil, I'd start with a tablespoon and see how that tastes, that add more 'til you like it.