In the interest of expanding my cooking knowledge, I didn’t listen. Although, they were right about the work.
Curd is made by combining dairy with something acidic, which reacts to create a thicker substance. So, you’ll usually need some combination of butter, lemons/oranges and sugar. Some recipes I found called for egg yolks so I also put those in, but it seemed like the proportions of the former ingredients varied a lot. Most advice pointed to using Seville oranges as they tend to be more bitter, but I couldn’t find any so tried to use less sugar.
It’s probably a case of trying out different methods until you find your favourite. Here is what I did, which was moderately sharp, but worked well with the cake.
Juice of 4 oranges and 1 lemon
Zest from 2 oranges and 1 lemon, finely chopped
About 1 cup (200g) butter
½ cup (100g) sugar
3 egg yolks
1. In a medium-sized saucepan over low heat, melt the butter. Using a wooden spoon, stir in the sugar until dissolved, then add the orange/lemon juice and zest.
2. Stir the mixture frequently. When you notice that it starts to thicken (around 10 minutes), keep stirring until the curd coats the back of the spoon when you lift it out (this really won’t happen on anything other than a wooden spoon – I tried!)