An aerated brew of compost, microbes and sometimes nutrients applied to soil or leaves. Jeremy notes teas are optional (you can just top dress) but many growers and plants benefit.
Jeremy explicitly says compost tea is about biology, that 'good compost is important' is the one thing nobody argues about, and that his basic recipe is 4 gallons water + 1.5 cups castings + 1/3 cup molasses aerated 24 hours.