The Accidental Supper — roasted onion and carrot lasagne

This was meant to be roasted onion risotto. I swear I saw a packet of arborio rice in the cupboard at the weekend. Or half a packet, or a third. I planned the whole dish, and wrote down the recipe. Then I reached to the top shelf to grab the arborio rice and… nada.

But no matter — in Thrifty January, we have to be adaptable. And luckily, there were exactly six lasagne sheets in a packet in another cupboard. So roasted onion lasagne it would be.

Onions were intended to be the only vegetable in it, but when I spied plump carrots in the crisper, I decided to roast those as well and include them in the dish.

The air fryer came into play for this, though it wouldn’t be entirely accurate to call it an air fryer recipe. 

This is occurring more and more in my kitchen — in the old days, before the advent of the air fryer, the big old oven would be the obvious, or only, choice for roasting vegetables. (No, I have never roasted anything in a microwave oven, even after many decades since their arrival in the modern kitchen, I rarely use it other than for thawing or reheating.)

But turning on the big gas oven seemed an unnecessary waste of time (and gas — this is Thrifty January after all), so I preheated an air fryer instead, to 180°C, and prepared the onions and carrots.

For lasagne, you need two sauces — a béchamel, and a second sauce, usually made chiefly of tomato. The latter needs to be fairly runny, and the béchamel need not be too thick either, as they are both tasked with the important job of being soaked up by the dry lasagne sheets while the lasagne is baking in the oven.

Allow yourself plenty of time when making a dish of this kind. Because there are several components, and consequently steps, it is not a dish to be whipped up in merely an hour. In fact, it needs a good 40 to 45 minutes in the oven, and that’s after all the preparation.

Tony’s roasted onion and carrot lasagne

(Serves 4 to 6)

Ingredients

6 medium onions

6 fairly large carrots

Cooking oil

Salt (or garlic salt) and black pepper

Grated cheddar cheese, as much as needed

For the tomato sauce:

1 small onion, finely chopped

Olive oil

A glass of dry white wine

1 x 400g can of Italian chopped tomatoes

250ml chicken (or vegetable) stock

1 Tbsp dried oregano

2 Tbsp sweet soy sauce

2 Tbsp marmalade (any)

1 heaped tsp cornflour dissolved in cold water

Salt and black pepper to taste

For the béchamel:

500ml full cream milk

1 Tbsp flour

2 Tbsp butter

1 bay leaf

A few gratings of nutmeg

Salt and white pepper to taste

Method

Peel all the onions. Cut three of them in half through the middle (not through the top and root ends). Cut the remaining three into quarters.

Pour a little cooking oil into a bowl, season with salt (or garlic salt) and black pepper, and toss the onions in it.

Preheat an air fryer to 200°C and, when hot enough, put all the onions in it, with the halved ones facing flat-side up.

Roast at 180°C until the tops of the halved onions display lovely golden rings and the flesh is soft. (Roast for 10, and later 5, minutes at a time, and stop when they look right to you.) Remove.

Top and tail the carrots, and peel them if you like. Slice them lengthways through the middle, and thicker ones into long quarters again. Chop them in halves or thirds too.

Add a little more oil to the bowl, and toss the carrots in it.

Put them in the same air fryer basket, and roast at 180°C until tender. Remove.

Next, make the tomato sauce. 

Chop the onion and simmer in olive oil until lightly golden.

Add a glass of dry white wine and reduce to a syrupy glaze.

Add the chopped tomatoes, stock and oregano, and simmer for about 10 minutes while the flavours develop. Stir as needed.

Pour in the dissolved cornflour and stir while the sauce thickens. 

Finally, season with salt and black pepper and stir in the sweet soy sauce and marmalade.

The last two ingredients are not traditional for an Italian tomato sauce, but an acidic tomato sauce needs to be cut by a little sweetness, and they both add a little “something” to the end result.

Meanwhile, preheat the conventional oven to 200°C.

Now make the béchamel.

Heat the milk to just before boiling point, with the bay leaf, grated nutmeg and salt and white pepper to taste. Remove from the heat and pour into a jug.

Melt butter in a heavy saucepan and, off the heat, stir in the flour to make a roux.

On a low heat, stir constantly while pouring in the heated milk a little at a time. If it seems very thick when all the milk has been used up, add more milk (cold is fine at this point) until it is a fairly thick sauce but runny enough to be absorbed by the lasagne while baking in the oven.

Grease a suitable oven dish (one that can hold about three lasagne sheets side by side) with butter on the base and sides.

Pour half of the tomato sauce into the base of the dish. Add three lasagne sheets in a row. Place some of the carrots and chopped onion on this, and top with béchamel.

Add three more lasagne sheets and top with the remaining tomato sauce.

On top of this, place the remaining carrots and chopped onions, and top with the remaining béchamel.

Now you’re left with the three halved onions that you roasted in the air fryer earlier.

Push them into the sauce so that their tops are even with the surrounding sauces. Check the photograph to see what I mean.

Finally, grate some Cheddar cheese (or another cheese you happen to have) and scatter it on top, but push the cheese off the rounds of onion so that they can shine through.

Bake in the preheated 200°C oven for 40 to 45 minutes. Turn the oven off and leave the lasagne to “set” for about 20 minutes before serving.

You could serve it with a side salad, I suppose, but I’ve never seen the point of it — it’s a meal in its own right. DM

Tony Jackman is twice winner of the Galliova Food Writer of the Year award, in 2021 and 2023

Order Tony’s book, foodSTUFF, here.

Follow Tony Jackman on Instagram @tony_jackman_cooks.