Keep cardamom pods and vanilla beans on hand so that you can make this jam throughout berry season. Simply simmered for 20 minutes, it works best made in small batches like this. Serve it warm over toast or vanilla ice cream, and keep any leftovers in the fridge. And if you have some on hand...Stir in a handful of raspberries with the strawberries.
Put the vanilla seeds and pod in a heavy, nonreactive skillet. Add the sugar, orange juice and cardamom pods and cook over medium heat, stirring occasionally, until the sugar dissolves, about 5 minutes.
Add the strawberries to the skillet and stir once to coat. Simmer, stirring occasionally, until the mixture is thick and jam-like, 20 to 25 minutes. (The longer the mixture cooks, the thicker the jam will be after it cools.) Remove from the heat and let cool before using. Discard the cardamom and vanilla pods before serving. (The jam will keep refrigerated for 2 weeks.)