Fill a saucepan with about 2 inches of water and bring to a simmer over medium to medium low.
In a heat-proof metal mixing bowl (one that can sit on top of the saucepan without touching the water) whisk together the egg yolks, sugar, orange juice and orange zest until smooth (1-2 minutes). (Note that 2 large navel oranges will yield enough zest and juice for this recipe).
Place the bowl over the saucepan. Stirring constantly with a silicone whisk or spatula, cook the mixture until thick enough to coat a spoon. (Note that this process can take anywhere from 7-15 minutes, depending on how fast the water is simmering, how close the bowl is to the water, etc. The mixture will not appear as thick and jellied as store-bought citrus curd, but will have the consistency of warm pudding. It will also thicken more when it cools.)
Remove the bowl from the heat, and add the slices of butter, one at a time, whisking well after each slice until the butter disappears. Pour the mixture through a mesh strainer, pushing it through with a spatula, to strain out the zest. (Note, it's fine if you want to skip this step, but straining out the zest yields a beautifully smooth and creamy curd.)
Pour into a glass jar and store in the fridge until ready to use. It will be at a spreadable consistency straight from the fridge, or you can gently rewarm it for a "pourable" consistency.
Yields about 1 2/3 cups.
Weight Watchers Points Plus Value: 2 points, per tablespoon
Recipe from Curly Girl Kitchen