Add 1/4 cup of chickpea flour to a heavy-bottomed saucepan and slowly whisk in 1 cup of water, stirring well to break up any lumps. Then let it sit for 5 minutes while you prepare the remaining ingredients.
Zest one large lemon into the saucepan, then slice it in half and squeeze out the juice into a measuring cup. Continue juicing the lemons until you have 3/4 cup.
Add the sugar, freshly squeezed lemon juice, salt, and a dash of turmeric to the saucepan and stir until well combined.
Turn on the heat to medium and stir frequently with a whisk. (The mixture will get foamy.)
Continue to stir frequently until the mixture begins to boil, then stir constantly while the lemon curd boils for 2 minutes.
Remove from the heat, add 4 tablespoons of vegan butter, and stir until well incorporated. (The lemon curd will be thin when hot, but will thicken as it cools.)
Notes
Be sure to let the chickpea flour and water mixture rest for at least 5 minutes before heating. This allows the flour to soften completely, removing the funny taste that chickpea flour has.
Don't taste the liquid before it's done cooking. Uncooked chickpea flour tastes terrible.
Be sure to continue to cook the lemon curd for 2 minutes after it begins to boil.