Shakshuka

What this is

Eggs poached directly in a spiced tomato and pepper sauce, cooked and served in the same pan.

It is the best breakfast on this list and one of the best cheap dinners, and it happens to combine two ingredients whose cooking has been studied carefully: tomatoes and eggs.

Both findings below argue for exactly the way this dish is traditionally made, which does not happen often.

Ingredients

For 2 servings

4 eggs 1 tin chopped tomatoes, about 400 g, or 500 g fresh tomatoes, chopped 2 red peppers, sliced 1 onion, sliced 3 cloves garlic, sliced 2 tbsp olive oil 1 tsp ground cumin 1 tsp sweet paprika Half tsp chilli flakes, more if you like Salt and black pepper

To serve: feta, fresh coriander or parsley, good bread, a drizzle of olive oil

Method

1. Heat the oil in a wide, shallow pan with a lid. Cook the onion and peppers over medium heat for 10 minutes until genuinely soft.

2. Add the garlic, cumin, paprika and chilli. Stir for 45 seconds.

3. Add the tomatoes and a splash of water. Simmer uncovered for 10 to 12 minutes until the sauce thickens and no longer looks watery. Do not simmer it for an hour, for a reason covered below.

4. Season the sauce now.

5. Make four wells in the sauce with the back of a spoon. Crack an egg into each.

6. Cover the pan and cook 5 to 7 minutes, until the whites are set and the yolks are still soft. Check at 5; residual heat keeps cooking them after the pan comes off.

7. Crumble feta over the top, add herbs and a final drizzle of oil.

8. Serve straight from the pan with bread.

Why poaching the eggs matters

This is the finding that justifies the whole method.

A study assessed how the cooking process affects nutrient digestibility and vitamin A and D3 bioaccessibility in eggs, comparing hard-boiled, poached and omelet. It used simulated digestion across three models mimicking gastrointestinal conditions in older adults, at oral, oral plus gastric, and oral plus gastric plus intestinal stages, alongside a healthy adult model.

The headline result: proteolysis, the breakdown of protein, was reduced after digestion of the omelet under the full model, by up to 37 percent.

Up to a third less protein breakdown from the omelet than the alternatives, under those conditions. The authors conclude that hard-boiled and poached were more recommendable to enhance protein digestibility.

And on the comparison between those two, the study is specific: digestion of nutrients depended on the resulting matrix, with poached being the greater supplier of protein and lipid end-digestion products.

Poached came out ahead.

Some reassurance in the same study: altered gastrointestinal conditions negatively influenced neither the absorbable lipid fraction nor cholesterol stability, and vitamin A bioaccessibility was unaffected, while D3 decreased slightly under the full elderly model. Poached and omelet both offered a high net supply of bioaccessible vitamin D3.

This used laboratory digestion models simulating conditions in older adults rather than measuring absorption in people, and the differences it found may not apply the same way to a young healthy digestive system. What it supports is that how you cook an egg changes what comes out of it, and that poaching is a good way to do it.

Cook the tomatoes, but do not cook them to death

The tomato instruction has real evidence behind it in both directions.

A study evaluated air frying and conventional baking of cherry tomatoes on the concentration and bioaccessible content of carotenoids, covering both coloured compounds, lycopene, beta-carotene, lutein and zeta-carotene, and colourless ones, phytoene and phytofluene. Tomatoes were cooked at 180 to 200C for 2 to 20 minutes, quantified by liquid chromatography, with bioaccessibility assessed using the standardised INFOGEST 2.0 digestion protocol.

Both methods improved total carotenoid bioaccessibility compared with raw tomatoes. That is the first half: cooking tomatoes makes their carotenoids more available than eating them raw.

Maximum bioaccessibility was reached at 190C for 10 minutes by air frying and 180C for 20 minutes by baking, with no significant difference between the two.

There is a peak, and it arrives quickly.

The second half is the caution. Colourless carotenoids were more thermally stable and bioaccessible than coloured ones, with phytoene and phytofluene retaining high bioaccessibility even after prolonged cooking, while lycopene was heat-sensitive.

Lycopene, the compound tomatoes are famous for, is the one that degrades. So a sauce simmered gently for 10 to 12 minutes is doing the job; a sauce reduced for an hour is past the point.

As an aside, air frying reduced energy consumption by 78.6 percent compared with baking, which is a genuinely large number if you cook tomatoes often.

This used cherry tomatoes in dry-heat cooking and a laboratory digestion model, not a wet tomato sauce on a hob, so the timings are a guide to the shape of the curve rather than settings for your pan.

What we do not know about the peppers

The peppers get less certainty, and it is worth saying so.

A review assessed the effect of heat processing on red pepper bioactive compounds and antioxidant capacity, searching Google Scholar and Scopus. Of 422 articles accessed, only 15 qualified for detailed review after inclusion and exclusion criteria.

Fifteen out of 422.

And the review's conclusion about those 15 is unusually blunt: many studies were incomprehensive on the details of processing conditions, which constrains the validity of the results obtained on cooking effects. It calls for further studies to better understand the heat processing conditions and factors involved.

So I cannot tell you what cooking does to the bioactive compounds in your peppers, and neither can anybody else with confidence. What I can tell you is that softening them properly is what makes this dish taste like something, which is reason enough for ten minutes.

This review found the underlying literature insufficiently detailed to draw firm conclusions, which is exactly why it is cited here rather than a claim about peppers being made.

Storage and swaps

The sauce keeps 4 days in the fridge and freezes for 3 months. The eggs do not, so make the sauce ahead and poach fresh eggs into a reheated portion. That is the single best meal prep trick on this list.

Swap feta for labneh, ricotta or nothing.

Add chickpeas or white beans to the sauce for bulk and fibre.

Add spinach in the last 2 minutes before the eggs go in.

And use a lid. Poaching eggs in an uncovered pan cooks them from below only, so you get set bottoms and raw tops.