Process strawberries in blender until smooth (if powerful, seeds should grind up and not need to be strained).
In a heavy saucepan, combine puree, sugar, lemon juice, and egg yolks. Cook over medium heat, whisking constantly, until very thick (approx 10 minutes). If you stir and drizzle a line of curd back into the pot, you should see a line of curd that takes a second or two to disappear.
Remove from heat; gradually add butter a couple pats at a time, whisking until melted.
Cool mixture slightly; cover and refrigerate for a couple hours until cool and further thickened. Store in refrigerator.
Notes
Tip: you can freeze the leftover egg whites (be sure to label with the number of whites in the container) for use in other recipes.
I am not a health professional and nutrition data is calculated programatically. Accuracy may vary with product selection, calculator accuracy, etc. Consult a professional for the best information.