Wash the mustard greens with cold water. Let them drain. Remove the leaves from the stems and cut the stems into 1-inch slices and leaves into 2-inch slices.
Heat the olive oil and saute the onions, stems, and mushrooms for five minutes. Add leaves, sesame oil, garlic, salt, and soy sauce. Stir until vegetables are tender to taste.
Wash the mustard greens with cold water. Let them drain. Remove the leaves from the stems and cut the stems into 1-inch slices and leaves into 2-inch slices.
Heat the olive oil and saute the onions, stems, and mushrooms for five minutes. Add leaves, sesame oil, garlic, salt, and soy sauce. Stir until vegetables are tender to taste.