Layer the strawberries with sugar in a bowl and allow to macerate in the refrigerator for at least 15 minutes or up to 4 hours.

Pour into a cast iron skillet; add jalapeno and lemon juice and simmer over medium heat until most of the liquid has evaporated and the jam has thickened, about 15 - 20 minutes.

Remove from heat and allow to cool to room temperature. Store in air-tight jar for up to 3 weeks in the refrigerator.