Cut a small x in stem end of each cauliflower floret.
If florets are large, cut them into 2 or 3 slices.
Cut a small x in stem end of broccoli florets.
Cut jicama into thick slices, then cut into 2x1/4 inch strips.
Set all vegetables, oil and seasonings near cooking area.
Heat vegetable oil in wok or large skillet over high heat.
Add ginger and stir-fry 10 seconds.
Add cauliflower and broccoli; stir-fry 30 seconds to coat with oil.
Pour about 1/3 cup of the chicken broth around edges of wok.
Add salt and sugar.
Cover and cook until vegetables are partially tender, 3 to 4 minutes.
Add jicama, bell pepper and remaining chicken broth.
Cover and cook 1 minute.
Uncover and stir-fry until vegetables are crisp-tender and all liquid has evaporated.
Stir in sesame oil.