honestly, I just take a little garlic and mash it up in a little bowl, then put butter in it. Then i stick it in the oven while the fish is cooking. Not fancy, but its good.
I always throw a stick of butter in a sauce pan and turn on low heat.
Peel a few garlic cloves and throw them in whole.
Simmer for a bit.
Squeeze in some lemon juice to taste.
Add a little lemon pepper and BAM !!!!!
You got it.
You can scrape the butter fat out if you like it clarified.