Wash rice thoroughly, then boil in 5 cups of water with the sea salt. Simmer until the rice is tender (about 45 minutes with brown rice.).
Slice onion finely. Cut radish in 4 pieces. Cut carrot on the diagonal in slices, then cut the slices in strips. Quarter the cucumber lengthwise, then slice. You don't have to peel it.
Heat oil in a saute pan and stir fry the garlic until it turns brown. Some fresh minced ginger may also be added. Add all the vegetables and stir fry for about 3 minutes. Add sesame seeds and stir fry for two more minutes. Turn off the heat and set aside.
Add veggies to the rice. Add soy sauce and lemon juice. Serve with tahini poured over all.