Start by washing your strawberries thoroughly. Remove the stems and hulls, then chop the strawberries into smaller pieces. Place them in your saucepan along with the granulated sugar and lemon juice. Cook over medium heat, stirring occasionally, until the strawberries have softened and released their juices—about 5 to 7 minutes.
Using a blender or immersion blender, puree the cooked strawberries until smooth. For the silkiest curd, strain the puree through a fine mesh sieve into a clean saucepan to remove seeds and pulp.
In a separate bowl, whisk together the 2 whole eggs and 3 egg yolks until fully combined. Slowly add the eggs to the strawberry puree in the saucepan, whisking constantly to prevent the eggs from scrambling.
Place the saucepan over low heat and cook the mixture gently, stirring continuously with a whisk or spatula. The curd will begin to thicken after about 8 to 10 minutes. It should coat the back of a spoon and leave a clear line when you run your finger through it.
Remove the saucepan from heat and immediately stir in the salted butter, piece by piece. Stir until fully incorporated, adding creaminess and a glossy finish.
Pour the finished Strawberry Curd into a heatproof bowl or jar. Allow it to cool to room temperature, then cover and refrigerate. The curd will thicken further as it chills and can be stored in the fridge for up to two weeks.