The best bok choy to use for roasting is the little tiny baby size. But we can almost never find it, so I've adapted the roasting directions for a piece that's a bit bigger!
Roasted Bok Choy
Baby or small heads of bok choy
Garlic salt (optional)
3 parts lemon juice
2 parts miso paste
1 part rice vinegar
Preheat oven to 425. Wash the bok choy and slice it lengthwise if it isn't baby-sized. Pat dry and arrange on a foil-lined baking sheet. Drizzle with olive oil and sprinkle lightly with garlic salt. Add a couple T of water to the bottom of the pan and cover with foil. Bake for about 5 minutes, remove the foil, and bake for 5 to 10 minutes more until leaves are crisp.
Whisk together the lemon juice, miso, and vinegar, and spoon sauce over bok choy once plated.