Gather all your ingredients: fresh lemons, sugar, cornstarch, whole milk, egg yolks, butter, and salt. Zest two lemons and juice them, ensuring you have about half a cup. Separate the egg yolks into a small bowl.

In a large saucepan, whisk together ¾ cup of sugar and ¼ cup of cornstarch until evenly blended. Ensure no lumps are present.

Pour in 2 ¾ cups of whole milk and add the separated egg yolks. Stir in a pinch of salt and the grated lemon zest. Mix until well combined.

Place the saucepan over medium heat, stirring constantly. Cook for about 8–10 minutes until the mixture thickens and coats the back of the spoon.

Once thickened, remove from heat. Add the fresh lemon juice and 2 tablespoons of butter, stirring until smooth and glossy.

Strain the pudding through a fine wire strainer into a clean bowl for a silky texture. Skip if you prefer a heartier texture.

Cover the bowl with plastic wrap and refrigerate for at least 2 hours.