One of the challenges of cooking from the forest garden is using the large amount of leaves, some bland, some quite strongly flavoured, that it produces. Over the years I’ve experimented with various ways of cooking with them, always with the rule that the result must be actively attractive to eat, not merely a way of using up a glut. One of the best is one of the simplest, cooking them together as pot herbs, but I now have a new favourite, leaf sauce!

In short, leaf sauce is a mix of leaves and shoots: steamed, blended and seasoned. Its strength is the opportunity that it gives to blend together lots of different flavours into something very rich and complex. So far the two killer apps I have found for it are pasta and curry, but I’m sure creative chefs could find many more.

The recipe… well, there is no exact recipe. The keys to making it are flexibility and diversity. It can be made at almost any time of year with whatever is at hand and available in the garden. The leaf sauce year begins in February or, in a cold year, March, with the emergence of the wild garlic and other leafy alliums and the start back into growth (in a mild year it hardly stops) of kale, sea beet and leaf celery. Not far behind these are two members of the dock family, herb patience and monk’s rhubarb.

Soon various spring shoots are starting to come up. Lovage, sweet cicely, alexanders, hogweed and ground elder are all excellent used this way. They are all strong-flavoured members of the carrot family that are somewhat milder when the new leaves are just emerging in spring and summer. Hogweed requires a little care in harvesting. Udo and its relatives are similar, and some members of the daisy family also produce tender leaves in spring, notably salsify and scorzonera (Scorzonera hispanica). Young hosta shoots are better used as vegetables but once they unfurl into leaves they can be used in the sauce. Nettles are good to use any time between their emergence and when they start to flower.

The trees also get in on the act. Lime trees in general and small-leaved lime in particular have succulent spring leaves. I’m also trialling toon (Toona sinensis), said to have edible leaves and shoots tasting of onions! Elm leaves aren’t edible, but their seeds are and they are produced in incredible abundance. Climbing up the trees you might find Hablitzia tamnoides, Caucasian climbing spinach.

As we get into summer, the annuals come into play, with more familiar crops such as spinach and mustard. Some crops better known for other parts also have usable leaves, including beetroot, broad beans, peas and radishes, and I’m not even going to try to list all the herbs that can be included.
In autumn, some of the plants that ran to seed and became unpalatable in summer have a second flush of fresh growth, including celery, herb patience and sweet cicely. Nasturtium also starts serious production around this time.

Even in winter there are still abundant ingredients for this dish. The pictures below are from a leaf sauce curry I made in November, with shiitake and oyster mushrooms, apples, broad beans and a vast array of roots, with a sauce from leeks, kale, celery, walking onions, sweet cicely, wasabi (leaves), common mallow and leaf beet.

Recipe (sort of)

1. Pick a lot of leaves and shoots. They will boil down a lot and leftover sauce is ideal for freezing, so it’s difficult to pick too many. I usually aim for a carrier bag full. Go for a good mix of types for depth of flavour, with a balance of bland and strongly flavoured ones. This is a bit trial and error and you will find out what you like best over time. For curries I usually go for a greater proportion of strongly flavoured ones and for pasta I add more Mediterranean herbs such as oregano.
2. Wash and drain and coarsely chop the leaves.
3. Chop and fry an onion. Once the onion goes clear, add garlic and any chopped or ground (not powdered) spices herbs that you like.
4. Fry a few minutes more. Add powdered spices, stir and fry very briefly. Throw in the leaves and add a little water so that the bottom of the pan is just covered with water. Sprinkle a little salt over the top if desired and put the lid on.
5. Steam the leaves for 15-20 min, topping up the water if the bottom of the pan ever looks like drying out.
6. Remove from the heat and liquidise the leaves. I use a small hand-held blender for this.
7. Now stir in any other flavourings you like, be it stock powder, curry paste, soy sauce, olive oil or whatever. When making curry I tend to get very eclectic as practically any flavour, if used at a level just below where you start to taste it individually, will add to the depth of flavour.

When it comes to combining the sauce with the rest of a dish, such as the chunky ingredients in a curry, I tend to cook them separately and combine them near the end as finished leaf sauce is thick enough to burn very easily on the hob if not stirred regularly. If you want to cook them together for longer it’s better to water it down a bit to avoid sticking.

Yes, apples are excellent in a curry.