Simmer the finely diced pineapple with 1/4 cup sugar and lemon juice for 10 minutes until softened and juices concentrate; keep the mixture at a gentle simmer. Visual cue: the fruit looks slightly translucent and syrupy around the edges.

Cool the pineapple mixture, then blend to a chunky puree; pulse only until it thickens but still shows small pineapple bits. Visual cue: you should see visible chunks rather than a fully smooth sauce.

Heat the heavy cream and whole milk until steaming, not boiling. Visual cue: small bubbles form around the edges and steam rises from the surface.

Slowly whisk the steaming dairy into the egg yolks beaten with the remaining 1/2 cup sugar to temper. Visual cue: the mixture turns lighter and smooth as it thickens slightly.

Cook the custard until it reaches 175°F, stirring constantly to prevent scrambling. Visual cue: it coats the back of a spoon and holds a clear line when you run your finger through it.

Strain the custard, then stir in the vanilla, salt, and pineapple puree. Visual cue: the mixture becomes vivid pale yellow with specks of pineapple throughout.

Cool completely, then refrigerate for 4 hours until cold through. Visual cue: the custard looks set and thoroughly chilled, not warm at all.

Churn in an ice cream maker according to the manufacturer’s instructions until thickened to soft-serve consistency. Visual cue: the ice cream looks fluffy and holds ridges from the churn.

Transfer to a container and freeze until firm. Visual cue: the texture becomes scoopable and dense with minimal melt at the edges.