4 cups hot cooked spaghetti (about 8 ounces uncooked pasta)
1 teaspoon dark sesame oil
1 tablespoon peanut oil
1 tablespoon minced peeled fresh ginger
4 garlic cloves, minced
3 cups chopped broccoli
1 1/2 cups vertically sliced onion
1 (1-pound) flank steak, trimmed and cut across the grain into long, thin strips
3 tablespoons low-sodium soy sauce
2 tablespoons brown sugar
1 tablespoon oyster sauce
1 tablespoon chile paste with garlic