1. Wash and cut rhubarb into 2-inch pieces. Process in a food processor until it becomes a pulp. Push the pulp through a fine sieve to extract all the juice, then discard the fibrous pulp. You should get about 1 1/4 cups of rhubarb juice.

2. In a food processor or mixing bowl, combine eggs, sugar, and cornstarch. Blend or whisk until smooth with no lumps remaining.

3. In a saucepan, combine 1 cup of rhubarb juice, the egg mixture, and cubed butter. Set over low heat and whisk constantly as the butter melts and the curd begins to thicken.

4. Continue cooking and whisking over low heat. Don’t rush by turning up the heat or the eggs will scramble. The curd is ready when it reaches the consistency of thick sour cream, about 15-20 minutes.

5. Remove from heat and push through a fine sieve again for silky smoothness. Stir in the remaining rhubarb juice to boost tartness and add a drop of pink food coloring if desired.

6. Transfer to clean jars and refrigerate for at least 3 hours or overnight. The curd will thicken further as it chills.