How do I fix undercooked food after serving?

What can be rescued, what must go back to the heat, and the things that are not safe to serve at all.

Difficulty: beginner
Time: 20 min
Read: 3 min
Safety: warning

Short answer

Take it back to the kitchen and finish it — carve or portion it first so it cooks through quickly. For poultry and mince there is no shortcut: it must reach a safe temperature, and looking cooked is not the test.

There are two different problems here. Undercooked potatoes are an inconvenience. Undercooked chicken is a health matter, and the fix has to be governed by that rather than by the awkwardness of taking plates back.

Safety

Undercooked poultry, pork, mince, burgers, sausages and reformed meats are a genuine food poisoning risk and must be cooked through — to 75°C in the centre, or 74°C for poultry. Do not serve them and do not judge by colour. If it has already been served and eaten, that is worth mentioning to a doctor if anyone becomes unwell.

Step by step

Decide whether it is a safety issue or a texture issue.Poultry, pork, mince, burgers and sausages must be cooked through. Vegetables, whole cuts of beef and lamb, and baked goods are texture problems.
Take the plates back without apology.Everyone would rather wait ten minutes than eat raw chicken. Hesitating over this is the only genuine mistake available here.
Increase the surface area before finishing it.Carve the joint, halve the potatoes, slice the chicken. It cooks through in a fraction of the time and far more evenly.
Use a fast, direct heat to finish.A hot pan, or the oven turned up. Portioned pieces in a hot pan are the quickest reliable route.
Check with a thermometer, not by eye.75°C in the centre for most meats, 74°C for poultry. Colour is not a reliable indicator — meat can be pink and safe, or brown and not.
Keep the rest of the meal warm.Cover the plates or put them in a low oven while the problem item finishes. This is the difference between a delay and a ruined meal.
For undercooked baking, judge whether it is salvageable.A slightly underdone cake can go back in, covered with foil. A collapsed one usually cannot, and is better repurposed than served.

Tips

A digital probe thermometer removes this problem almost entirely, and costs less than one ruined joint of meat.
If people have already started eating an item that must be cooked through, say so plainly. Embarrassment is not worth the risk.
Resting time is not cooking time, but a large joint does keep rising a few degrees after it leaves the oven — worth accounting for.

Common mistakes

Judging doneness by colour — Meat can be pink and perfectly safe, or brown and undercooked. Temperature is the only reliable measure.
Microwaving undercooked chicken to finish it — Microwaves heat very unevenly and readily leave cold spots. Use a pan or oven and check with a thermometer.

If it doesn't work

Roast chicken pink at the bone

Cause: Not cooked to temperature, or served straight from a cold start — Fix: Joint it and return the pieces to a hot oven until 74°C throughout. Do not serve it and hope.

Potatoes hard in the middle

Cause: Pieces too large, or oven not hot enough — Fix: Halve them and return to a hot oven or a pan. They finish quickly once the surface area increases.

Rice still crunchy

Cause: Too little water, or the heat was too high — Fix: Add a splash of boiling water, cover and steam on a low heat for a few more minutes.

Cake wet in the centre

Cause: Oven too hot, so the outside set first — Fix: Cover with foil and return to a lower oven. If it has already sunk, accept it and serve it as something else.

Questions people ask

Can I put undercooked meat back in the oven?

Yes, and you should. Portion or carve it first so it cooks through quickly and evenly, and check the temperature rather than the colour.

What temperature should meat reach?

Broadly 75°C in the centre, and 74°C for poultry. Whole cuts of beef and lamb are a separate case where the outside is what matters.