Ahhh, I get it. I am a big EVOO fan. Just cut the top of the onion off, leave the bottom intact, and get rid of the outer skin. You can rub it with butter or EVOO then apply your favorite rub, or just SPOG. Pop the onions in the smoker at 250F with hickory (or any wood of choice) until done. Don't bother putting them in a foil pouch unless you leave it open so the onion can be exposed to the smoke.
When I did the stew I halved the cleaned and prepped onions and potatoes. For the cleaned carrots I just snipped off the ends. I de-shelled the garlic cloves then coated everything, including the meat, in EVOO. I sprinkled Snider's Roast Beef Seasoning on everything, then smoked it all for 3-4 hours.
Then I cubed the meat and potatoes, sliced the onions and carrots, chopped the garlic, added a little flour then my liquids (garlic infused beef broth, canned fire roasted tomatoes, sweet pomegranate balsamic vinegar, and a red wine reduction) to a big Dutch oven. Simmer until the meat tender and the veggies cooked.
That red wine reduction (whole bottle, minus one glass because, well, you know) and fire roasted tomatoes beef stew is my absolute favorite that I've made many, many times. Hickory smoking the meat and veggies took it to a wow level beyond even my expectations.