No recipe, but some experience to share. I have one of the big grills with a firebox on the side. Works good as a smoker. I use rubs and the occasional beer based marinade and have had good results.
Then I tried to smoke vegetables (zucchini steaks)  as I grill veggies all the time.  Wasted good veggies, the smoke flavor was so strong even I couldn't eat them. I smoked them when finishing some meat, but it was a mistake. If there is a next time, I'll stay with just the veggies and back off the amount of hickory used.
Dadman