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If you love grilled onions, this recipe is going to be a new favorite. Sweet Vidalia onions are hollowed out, seasoned, wrapped in thick-cut bacon, and slow-smoked until soft and deeply smoky. A savory basting sauce pools in the center, and melted Gruyere takes it completely over the top.
Why You’ll Love This
- That smoky depth — two hours on the smoker transforms these into something completely different from anything you’d get on a regular grill
- The basting sauce is everything — beef broth and vermouth pool in the center of each onion and go almost soup-like by the end; completely savory and addictive
- Bacon that actually does something — it renders slowly and bastes the outside of the onion as it crisps up, not just a wrapper
- Gruyere makes it feel fancy — nuttier and more complex than cheddar, it melts beautifully right into that savory center
- Total crowd-stopper — serve these as a side and watch everyone get very quiet and very focused
A Few Notes on the Ingredients
The onions: You want Vidalia, small to medium size. Not the giant ones. Those take forever and the outer layers get weird. Vidalias are sweet and that sweetness plays really well against the smokiness — I’ve tried yellow onions in a pinch and they’re fine but they’re not the same thing.
The bacon: Thick cut. Please. Regular thin bacon basically disintegrates on the smoker and you lose that slightly-crisp-on-the-outside thing that makes this work. I usually just grab whatever thick-cut is at the store. Doesn’t have to be anything special.
Dry vermouth: I know some people don’t keep this around. I do — I use it in a lot of things, a splash here, a splash there — but if you don’t have it, dry white wine works fine. I’ve also made it with just extra beef broth and a squeeze of lemon when I was in a hurry and it was still very good. Not quite the same depth, but still very good.
Montreal seasoning: I use it twice in this recipe — on the onion itself and in the basting sauce — and it does a lot of the heavy lifting. I’ve been using McCormick brand for years, I don’t have strong feelings about it, just don’t skimp on the amount. It should look like a lot.
The Gruyere: Buy a block and slice it yourself if you can. Pre-shredded doesn’t melt as nicely. I tear it into pieces rather than layering it in neat slices because I like the rustic look and also I’m usually a little pressed for time by hour two of smoking anything.
Ingredients
- 4 Vidalia onions, small to medium
- About 2 tablespoons olive oil — I use extra virgin but honestly it doesn’t matter much here
- 1½ tablespoons Montreal seasoning
- 4 slices thick-cut bacon
- 4 ounces Gruyere, sliced and torn (I usually do a little more because why not)
- 2 tablespoons flat-leaf parsley, chopped — for garnish, don’t skip it, the color is pretty
For the basting sauce:
- ¾ cup beef broth
- ¼ cup dry vermouth
- ¼ teaspoon lemon thyme — if you can’t find lemon thyme, regular thyme is fine, maybe a tiny squeeze of lemon too
- ½ tablespoon Montreal seasoning
How to Make Them
First thing: prep your onions. Peel them — and leave them mostly intact, you’re not cutting them in half or anything. Slice about half an inch off the top. Trim the very bottom just barely, just enough so they’ll sit flat without rolling around. This matters more than you’d think because if they tip over on the grate you lose all that gorgeous basting liquid.
Now take a spoon — a regular dinner spoon works fine — and scoop out a few of the inner layers. You’re making a little well in the center. Don’t go crazy, don’t hollow the whole thing out. You want most of the outer layers intact because they’re what holds everything together. I’ve misjudged this and taken out too much and the onion basically falls apart by hour one. Leave more than you think you need to.
Brush your onions all over with olive oil, then hit them generously with the Montreal seasoning. More than looks reasonable. The smoking process takes some of that intensity down.
Wrap one slice of bacon around each onion — start at the base, wind it up toward the top, and secure it with a toothpick. The toothpick is doing real work here so don’t skip it.
Get your smoker going to 250°F. While it’s coming up to temp, mix together your basting sauce in a little bowl or measuring cup — broth, vermouth, thyme, seasoning. Give it a stir.
Spoon about two tablespoons of the sauce right into the center well of each onion before they go on. They’ll go on the grate and you’ll close the lid and try to leave them alone for thirty minutes. I know. It’s hard.
Every thirty minutes, open the smoker and baste. I use a spoon rather than a brush because I want the liquid to pool back in that center well — I’m not just coating the outside, I’m refilling the cup. After two hours the onions should be deeply soft when you poke them, the bacon should be just slightly crisped at the edges, and the whole thing should look collapsed and a little caramelized.
Those last five to ten minutes — tuck the Gruyere in. Some inside the well, some draped over the top. Close the lid, let it melt. Keep an eye on it because it goes from perfect to running-off-the-onion faster than you’d expect.
Pull them, scatter the parsley over the top, and let them sit for just a minute or two before serving. They’re very hot inside — that well holds heat like you wouldn’t believe.
Variations
There’s a version with blue cheese instead of Gruyere that’s actually really good if you like blue cheese. You can also skip the vermouth entirely and use a darker beer in the basting sauce — a porter or something — and that gives it a slightly different, maltier quality.
I tried once doing these in the oven on a low broil when the smoker wasn’t going to happen. They were okay. The bacon crisped up fine, the cheese melted beautifully — but that smokiness just wasn’t there, and that smokiness is really the whole point of the thing. If you don’t have a smoker, I’ve heard a charcoal grill with wood chips works well enough. I haven’t tried it myself. Someone at a cookout told me this and it sounded plausible.
Storing Leftovers
There are rarely leftovers, I’ll just say that upfront. But if you do have extra — cover them and refrigerate. They reheat okay in a low oven, maybe 300°F for fifteen minutes or so, though the bacon softens. I’ve eaten one cold the next morning, standing over the sink, and I don’t regret it at all. The flavors actually deepen overnight in a way I didn’t expect.
Smoked Bacon-Wrapped Vidalia Onions
Ingredients
- 4 Vidalia onions small to medium
- 2 tbsp olive oil
- 1 1/2 tbsp Montreal seasoning
- 4 slices bacon thick-cut
- 4 oz Gruyere cheese sliced and torn
- 2 tbsp parsley flat-leaf, chopped
- 3/4 cup beef broth
- 1/4 cup dry vermouth
- 1/4 tsp lemon thyme
- 1/2 tbsp Montreal seasoning for basting sauce
Instructions
- Peel onions, slice off the tops, and trim the bottoms so they sit flat. Scoop out a small well from the center of each onion.
- Brush onions with olive oil and season generously with Montreal seasoning.
- Wrap each onion with a slice of bacon and secure with a toothpick.
- Preheat smoker to 250°F. Mix beef broth, vermouth, thyme, and seasoning to make the basting sauce.
- Spoon about 2 tablespoons of basting liquid into the center of each onion and place them on the smoker.
- Smoke for about 2 hours, basting every 30 minutes, until onions are tender and bacon is slightly crisp.
- Add Gruyere cheese to the center and top of each onion during the last 5–10 minutes of cooking and let melt.
- Remove from smoker, garnish with parsley, and let rest briefly before serving.