No boil. Dry the leaves and pulverize leaves in a mortar & pestle (the powder will be green). It only takes 1/32 of a tsp to sweeten 2 litres of tea, because we like vaguely sweet tea). In the business they call it a “donk”, and it is hard to find measuring spoons with that small measurement.
Discussion
Did you start the stevia from seeds, or a seedling that had already started? My spouse uses stevia often, so I’d be interested in trying to grow some.
I got the plant from an herbalist. I daresay you could start from seed though. Although some plants will not do well from seed, I imagine you could find it easily enough. I will check when it flowers, and if it seeds, I will save some for you.