Bring 5/8 pt water to boil and add salt. Gather the spinach into a large bouquet, place it in the saucepan, and cover tightly. Cook for 5 minutes until the upper leaves begin to wilt. Immediately drain and plunge into cold water. Cut away the stalks and discard. Squeeze the leaves dry. Cut the leavesinto 1" pieces and squeeze them dry again. Set aside
Heat a heavy fry pan until water skitters accross surface. Add seeds, and warm for 3-4 minutes, shaking constantly.
Put the dashi, sugar, soy sauce and Msg into a small saucepan, stir and bring to a boil over high heat. Remove from heat and serve. To Serve: Pour sauce over the spinach and toss together to coat leaves. Divide into 6 bowls and sprinkle with sesame seeds.