The most important thing to remember when cooking with lupin is that lupin is a bean, and therefore behaves much like any other bean. I've written extensively about lupins in the past. In this post I summarize some of that knowledge, and give some general tips and tricks for cooking with lupins.
In particular, most any recipe for chickpea or soy bean can be adapted for lupin. Lupin flour can be directly substituted for chickpea flour (besan).
For flour recipes, you may have to alter the water ratio, or maybe add a little wheat flour to make it more cohesive. Also remember that lupin flour makes things sticky when you eat it, so things like lupin cookies and lupin crackers will usually be more chewy than those made with other flours. I don't think that's bad, you just need to remember to keep a glass of water handy when you eat lupin flour products. I've successfully made both lupin cookies and crackers.
For bean recipes, lupins can work as a drop-in substitute for most any bean. Lupins tend to be one of the toughest, thickest-skinned bean, so cook times with lupins will almost always be longer than with other beans. However, if you cook a lupin long enough, it will eventually get soft and creamy. Refried lupins are not only possible, they are also delicious.
Lupin sprouts can be used in any recipe calling for bean sprouts. Lupin sprouts are somewhat larger and tougher than typical bean sprouts (mung bean sprouts), but that usually isn't a problem. Lupins can be sprouted in exactly the same way as mung beans. The fact that lupin beans are bigger than mung beans actually makes sprouting them a bit more convenient because you can wash them with any colander without worrying about them slipping through the holes.
Drawbacks of lupin sprouts are that the germination rate is only about 80%, so you have to pick out the unsprouted seeds before serving the sprouts. Another draw back is that the hulls are thick and unappetizing, so they need to be removed before serving the sprouts. Removing the hulls can be time consuming.
I've discovered that lupin paste is an extremely versatile ingredient and can be used as a general purpose thickener, or as a base for many different kinds of dishes, such as sauces, soups, pie fillings, smoothies, hummus, etc. Lupin paste is made by soaking lupins over night and boiling them until they are at the desired softness (30 minutes for tough, chunky paste, up to 2.5 hours for a very smooth paste), and then blending them with water and/or oil to the desired consistency. A pressure cooker is very helpful when making lupin paste, as the beans will get softer and cook more quickly than with boiling without pressure.
Areas of ongoing research:
How well does lupin aquafaba work? Is it possible to make lupin meringue?
Easier ways to make lupin ice cream (can it be made from a smooth lupin paste? answer: Yes!)
How to make lupin ice cream less bitter (perhaps using lupin paste would help with this also. answer: just use lupin paste, water and sugar)
uses of lupins
Lopino sweet lupins
Australian sweet lupin information
Lupin milk recipe
Great resource for soy recipes (which can be adapted for lupin)