Field Company Cast Iron Seasoning Oil, 2 oz tin (856133007214). Official ingredients are organic grapeseed oil, organic sunflower oil, and beeswax. Field's Method is: after a warm-water rinse and drying the pan on the stove, apply about 1/4 teaspoon, rub all surfaces, and wipe to a dry matte finish. Official page says use within one year or refrigerate. Specs from Field Company's Cast Iron Seasoning Oil page (2 oz tin).
The 2 oz tin that lives next to the Field pans. A dab after you cook.