It’s difficult to think of a savoury dish that doesn’t start with a chopped and softened onion. These crunchy, many-layered bulbs add a sweetness and background savour to a host of dishes. Slicing and softening onions is, therefore, a basic cooking skill. It’s not difficult but takes a little love and attention.
Usually, we don’t want the onions to go brown, or if we do, we want that process to be very slow and controlled. Slow browning, caramelisation, means cooking onions at high enough temperature to get browning flavours (we want to start the Maillard processes, the magic that turns proteins and sugars to brown yumminess) but not so high that it burns. This can be difficult. A few brown pieces of onion won’t affect most dishes, but can add a pleasant ‘roast onion’ flavour.
The trick is to heat the onions slowly.
- Pot or frying pan
- Spatula or wooden spoon
- Fat (oil, butter or a bit of both)
- Heat the fat, add the onions and stir for half a minute or so.
- Lower the temperature. It should be hot enough to bubble softly, not so hot the fat crackles.
- Stir regularly. The onions are ready when they are almost transparent and soft. If you can easily divide a piece in two by pressing it lightly with the spatula or spoon, it’s soft.
- Keep an eye on them: if the edges start going brown, take the onions off the heat to stop the process before returning them, and lower the heat further.