Garlic shrimp reheats surprisingly well, so yes, you can make the whole thing in advance. You can also make the sauce and the herb paste in advance if you want it to still be "cooked fresh". The sauce will last indefinitely in the fridge, the herb paste will be good for a few days in an airtight container in the fridge. You can also sear the shrimp ahead of time, but if you do, don't wash the wok before you do the final cook, as the oil and any bits stuck to the pan are all good flavour. If you have to wash the wok, just scrape all the oil and the bits out and save them so you don't lose that goodness!