Most Egyptians eat koshari at least once a week. It's the kind of meal a parent makes for a hungry family, that street stalls sell to busy workers, that students eat between lessons. Whole restaurants in Cairo serve only koshari and nothing else.
What makes it special is that almost everything in it came from somewhere different. Rice came to Egypt from Asia. Pasta came from Italy. Lentils and chickpeas have grown in Egypt for thousands of years. The tomato sauce came from the Americas. Put it all together on one plate and you have a tasty world tour.
It is also a cheap and filling dish, which is why Egyptians made it their national food. A bowl of koshari can keep you going for hours, costs very little, and tastes brilliant. It happens to be entirely vegetarian too - no meat, just spices.
Eating koshari is a bit of a ritual. You mix everything together with a spoon until the crispy onions, sauce, lentils and pasta all coat each layer. Some people like a splash of vinegar and garlic sauce on top. The whole plate becomes a little messier - and a lot more delicious.