I wanted to make a courgette raita as well, but discovered we'd almost run out of yogurt, so today I made some more. Like bean-sprouts, I've been making my own yogurt for years. It's easy and it's cheaper than buying the stuff. It's also satisfying and fun to make things.
You boil a pint or so of milk (skimmed will work just as well as full-fat or anything in between), then cool it to blood temperature, which is a bit hotter than you think. Then you stir in a tablespoon of live yogurt. I use the last bit of the old batch unless it fails or goes mouldy, in which case I buy a small pot at the health food shop. Then you need to keep it warm for a few hours. I have a yogurt maker that is a sort of wide-necked thermos flask, and another type that is more like an electric incubator. I have to say the incubator type is more reliable.
After a few hours (or overnight) you'll have thickened plain yogurt. You'll want to chill it because warm yogurt is kind of yukky. You can add syrup and fruit to make it more like shop-bought fruit yogurt. I like it with sliced banana and maple syrup. Or you can use it for cooking, for salad dressings, smoothies or frozen yogurt and even make a kind of soft cheese. I'll talk about that in a future post.
One of these days I will make yogurt with milk from my own cow or goat. I'm looking forward to that.
Grate a couple of courgettes, mix with a teaspoon of ground sea salt then put them in a colander and leave them to drain for an hour or so. Squeeze any remaining liquid out of the courgettes with clean hands, then mix them with about a half pint of home-made plain yogurt. Heat 1 tsp black onion seeds in a dry frying pan and keep them moving until they start to pop, then quickly tip them onto the yogurt/courgette mixture. Add freshly ground black pepper, and a crushed clove of garlic, and more salt if necessary. Stir well and refrigerate until needed. Serve with crudites and mini popadoms as a dip, or as a side dish with an Indian meal. It is excellent for cooling your mouth when eating very spicy dishes.