I notice that there are few suggestions for the leeks.
I use them (1 per person) thinly sliced (across) as the main vegetable in stir-fry meals. I am not an expert cook but a stir fry makes a nice change, uses lots of vegetable, cooks quickly (prep takes longer though) and can be served with several sorts of meat or fish.
The cooking oil is flavoured with chilli flakes, crushed garlic and ginger mixed before you start cooking. You can uses up to a teaspoon of chilli and 2 teaspoons of crushed garlic and the same of ginger to suit your taste. I would start with about half these amounts so as not to kill anyone! You can increase these or reduce from there as you get used to the result. You need about half a cup of light oil - peanut is nice or rape will do. The vegetables have to be cut thin to cook quickly as does the meat or fish.
Other vegetables can be anything green (cabbage, pak choi, chinese lettuce, etc), mushrooms, peppers, red onion, etc. The choice is basically whatever is available. I haven't tried root veg but it might work if very thinly sliced and there is not too much. I usually use 2 or 3 veg but more is better as long as you don't overdo the total quantity. Try to mix colours to make the meal look interesting.
The meat/fish options are anything handy the will slice thinly and is reasonably tender. This includes chicken, pork, beef, prawns, salmon, trout. You don't need a lot of meat/fish. You can also add toasted nuts like almonds or cashews for interest.
Serve over white or brown rice or any of the oriental noodles (spaghetti would do as well).
I don't have a wok or a powerful burner on my stove so I cook each component - starting with the leaks then peppers - in a thin bottomed stainless frying pan which gets hot quickly. Each component is then parked in a glass bowl with the mixture being stirred as the next veg is added. The first veg continues to soften in the bowl from the residual heat so don't overcook in the pan. The veg mix is then placed on the rice/noodles and the meat/fish placed on top of that.
Cooking the veg and meat takes no more than 10 minutes, usually nearer 5. The rice/noodles take 15-20 minutes so they are started first.
Leaks cooked this way are not chewy or stringy and their slight onion flavour goes well in the mix. Red onions can also be used with them as they don't have a strong flavour either but I would avoid white onions with the leaks.
NN