Onion slices

Half-inch slices, two to three minutes a side. Fast, and structurally fragile the moment the layers relax.

What it is

Form: Cut vegetable
Typical weight: 100–200 g
Typical thickness: 12–15 mm
Cut: Not a cut of anything

Why it behaves as it does

An onion is concentric layers joined only at the root, so a slice is a stack of loose rings held by nothing once it softens. Iowa State's two to three minutes a side is short enough that the rings are still attached when they come off; the common failure is turning early and leaving half the slice behind. Leaving a little of the root end on each slice holds it together, and a skewer through the side does the same job.

When is it done?

Food-safety endpoint

BBQHQ holds no food-safety rule for this food. We are not showing you another jurisdiction’s figure in its place — check your national food-safety authority.

Texture endpoint — how you actually know

Softened but still in one piece

The rings have relaxed and coloured but the slice has not disintegrated. Turning it too early is what separates the rings, not cooking it too long.

How long it takes

Onion slices, grilled

Estimated cooking window

4 min–6 min

Low confidence

Why this is a range, not a number

Cookers hold temperature imperfectly
Individual animals and pieces differ

Cook to the endpoint, not to the clock. The window tells you when to start checking.

What this rests on

BBQHQ publishes a window for this cook.

Observations: 1
Documents: 1
Publishers timing this cook: 1

Iowa State University Extension and Outreach

Why confidence is not higher

At least one source does not state the cooker temperature.

How the sources were combined

ONE PUBLISHER, AND A PER-SIDE FIGURE MADE INTO A TOTAL. Iowa State gives 2–3 minutes per side on a medium-high grill; the 4–6 published here assumes one turn, which is the arrangement the article describes. That step is BBQHQ's and is declared rather than absorbed.

What makes the window as wide as it is

Cookers hold temperature imperfectly
Individual animals and pieces differ

When it goes wrong

Burnt outside, underdone inside: Vegetables charred outside and hard in the middle — 2 distinguishable causes.
It fell apart: Layered vegetables falling apart on the grate — 2 distinguishable causes.
It fell through the grate: Vegetables falling through the grate — 2 distinguishable causes.

Afterwards

Cooling, keeping and reheating what is left is general guidance for barbecue leftovers. Neither UK authority publishes anything specific to onion slices, and BBQHQ does not invent a distinction they do not make.