Okinawa spinach

I should have posted this before I ordered, oh well. I ordered Okinawa spinach.  It sounds like a great alturnative to lettuce, which I can only grow in the winter, and most of the time it is so bitter no one wants to eat it.  I'm very interested in perennial vegetables.  I just planted egyptian walking onions and potato onions. I hope they grow.  My Okinawa spinach should be here Friday.  Does anyone grow okinawa spinach? If so do you like it?  Any thing I should know, tips or trick's?  I live in Northern California zone 9b.  I would also love suggestions on perennial vegetables that will grow in my area, and taste good.  I keep thinking I will plant asparagus, but I have to find an area I'm willing to give for a veggie I can't eat for 3 years, and I don't do it.  Which is stupid because I have been thinking about it for a couple of years now.  Would have should have.  Thanks.

I haven't tried Okinawa spinach, but here's my two cents on three other perennial vegetables.

I ordered New Zealand Spinach and Good King Henry seeds though I'd never eaten them before. These were not a success for me. It turns out I didn't like to eat either of them, though I usually like all kinds of greens, raw and as salad. But Good King Henry was bitter in a way that I didn't like (though I do like some bitter vegetables), and I guess I'm one of the people who taste something unpleasant, sort of metallic, in NZ spinach. It's disappointing, because NZ spinach turns out to do great in my greenhouse, is very productive, perennial and vigorous in my passive solar greenhouse despite a month or two of frosted nights, and gets much less of the aphids that plague most things in the greenhouse this time of year.

Asparagus, I had of course eaten and loved before. I planted it from seed, first in 1-liter tetrapaks in summer, and then transplanted into place the following spring. It's so worth it! Just do it tomorrow. It is not a high volume producer for the space it takes up, but if you've got enough space, go for it. It's attractive in the background, a big bush of fluffy greenery all summer, so that's a good thing, and in autumn when you cut it down it makes a big pile of bright golden fluffy ornamental mulch, another good thing. And I'd never known how sweet and yummy it is raw until I grew my own.

I have never grown Okinawan spinach, but I got some info from the Korean site.
Here is the Google translation.

Hong Bongchae(紅鳳菜, Gynura bicolor): The back side of the leaf is purple. It is called Geumshicho in Japan and Hongbongchae in China.
It contains anthocyanin, an antioxidant, in addition to its effectiveness. It is good for improving immunity, improving eyesight, and inhibiting skin aging.

[Growth environment]
The proper growth temperature is 10~25℃, and the subtropical alpine zone is Wonsan. In the lowlands, it is better to shade indirect light or 20~30% of light rather than direct sunlight. In winter, it should be kept above 5℃.

[breeding]
It can be propagated by seed, seeding, cutting, and mainly by cutting.

[How to eat Myeongwol early (10-15 sheets per day)]
1. Chew 3-5 sheets before meals and eat with water or grind in a mixer.
2. Whenever you eat, take 3-5 sheets into wraps and eat them.
3. If you eat meat wrapped in wraps as a vegetable, the crunchiness and taste are excellent.
4. Take pickles and eat them, (Super pickled method is excellent)
5. After drying in the shade, it is good as bibimbap like gondre rice.
6. Make a salad with various vegetables and eat it.
7. Make it with rice and eat it. Grind 3-5 pieces of rice in a mixer and mix with water
8. In winter, drink dried powder or leaves as tea (boil 10 pieces into 3 cups with 4 cups of water)
9. You can bake the pancakes with pancake powder on the leaves, or chop the pancakes and fry pancakes with leeks.
10. Other methods include noodles, kimchi, water kimchi, pickles, and bondage.

[Source] Early Myeongwol/Hong Bongchae -Tree Love Gardening

Thanks for your insight.  
Jeesun I appreciate all the great information.  
Robecca  good king henry like spinach has lots of oxalic acid.  It blocks absorption of iron and calcium, but brakes down under high heat.  It's actually bad for humans to eat lots of raw spinach.  I wonder if the off putting taste is the body's way of telling us we shouldn't eat it.  Have you tried cooking good king henry? Maybe you would like it better that way?
Thank you both.