in a small bowl, combine soy sauce, lemon juice, corn starch, brown sugar, garlic and pepper. mix well. set aside
heat 1tbl. vegetable oil in a large skillet or wok over medium-high heat. add beef and cook until almost done. about 2 minutes. transfer beef to a bowl and cover to keep warm. set aside
cut broccoli into florets. heat remaining oil in same skillet. add onions and saute for about 5 minutes. add broccoli and mushrooms and water. bring to boil, cover and reduce heat to a simmer for 3 minutes.
return beef to skillet. add soy sauce mixture and ginger. bring to a boil. stir constantly and cook until sauce thickens. about 2 min.
serve hot over rice. enjoy!
variation: instead of the soy sauce in step one.. add 1/2 cup black bean sauce. and serve over egg noodles and top with toasted sesame seeds.
