Grapefruit Curd

Actually, it's the same like lemon curd except that this is made with grapefruit. 

I've got a few kilograms of grapefruit last week and was told that they are really sour, so not good for eating but for jam or similar. 
We have tasted and found it all right. They taste just like grapefruit. Sour. 
People nowadays don't like sour fruits, do they? I'm from Hungary and we LOVE sour cherries. Here, in Australia, fresh sour cherry is not available. At all. There is no demand for them. Even dried sour cherries are sweetened! How pity. 
Sour fruits are good, I think.
Anyway, I had these beautiful grapefruit and although my first thought was to make jam, I changed my mind and made some grapefruit curd. It's so delicious that in the end I saved all the juice and freeze them to make more curd in the future. 
Christmas is coming in the end and this will be a great present as well :)

Ingredients
4 eggs
1/2 cup (100 g) Natvia or other paleo sweetener
1/2 cup (~70 ml) fresh grapefruit juice (about half a grapefruit)
1/2 cup (~70 ml) ghee

Bring a large saucepan of water to a boil over medium-high heat.
Decrease the heat to low.
Whisk the eggs, Natvia, grapefruit juice in a medium stainless steel or glass bowl to blend.
Place the bowl over the hot water and whisk in the butter.
Continue to whisk for about 3 minutes or until the curd has become thick and creamy.
Remove from the heat and whisk until most of the heat from the curd dissipates.
Store covered in the refrigerator until serving.

Variations for wellbeing

Dairy intolerance: enjoy as is.
Gluten intolerance: enjoy as is.
Paleo: enjoy as is. Ghee is not recommended for people with autoimmune disease.