20 Tablespoons of peanut butter?

Without it having been tested and with no comments, I'd guess that the author meant 2 tablespoons, not 20. Have you thought about messaging them directly?

Haven't made this but have cooked many times with spice peanut sauce on various proteins.
The peanut butter amount might be just right or might be too much for one dish. Two ways to deal with it...
1) blend the ingredients that would make the sauce (including pb) and add only as much as you need to frying pan. If you use it all, fine. If not, put the rest in a closed jar in the fridge for about a week for other use.
2) make the recipe as directed but use only a portion (half or one-third, what looks good to you) in the frying pan at first. Add more if/as needed.
Would love to hear what amount worked out well.