I opted to start the seed in pots. Once germinated, I gently transplant them into individual growing cells. Then once they are big enough to handle easily, generally 4 leaf stage, they go out into the garden. I'm using the plastic bottle hotcaps for the first week or so, followed by a plastic collar. So far I've had very good success with almost no seedling loss.
This variety lives up to its reputation of quickly growing. Within 3 weeks out in the garden, I was sampling baby choys. Two weeks later the plants were big, lush, and mature.
(Not bolting yet....that is, no flower being produced.)
What hadn't been harvested at this stage were in the brink of bolting. One week later a few plants were bolting though others were still holding ok and getting bigger yet.
(Bolting. Flowering, plus the plant stem is growing longer, making the plant get taller. I ate this plant and it was fine tasting even at this stage.)
This variety is a definite keeper in my gardens. I grew it out in the full sun. I now plan to try some in semi shade and see what happens. I have a lot more semi shade than sun gardens, so I'm always looking for veggies that will produce in my less than ideal veggie locations.