Add a large pot of salted water to the stove and heat on high.
Heat peanut oil in a large saute pan or wok, on medium. Add onion and ginger to hot oil and saute for 2 minutes.
Add the garli and the rest of the veggies, stir, and saute for 7-8 minutes or until veggies are softened.
Meanwhile, whisk together the soy sauce, oyster sauce, hoisin, lime juice, and cornstarch.
When the water comes to a boil, add noodles and cook for 3-4 minutes, or however long the noodle package states. If using fresh noodles, only about 2 minutes.
Just before the noodles are done, scoop out 1/2 cup of the noodle water and add to the sauce. Drain noodles, but do not rinse!
Add sauce to the pan, and saute for a minute to heat before adding noodles, using tongs to coat noodles and veggies in the sauce. Saute for another minute to coat all of the noodles in the sauce.
Top with green onions, fresh cilantro, and a squeeze of half a lime and serve!