Beef Yakisoba Stir Fry

Name: Beef Yakisoba Stir Fry
Ingredients: 1 pound sirloin steak, sliced into strips or cubes (Or what you prefer ); 1 yellow or red bell pepper, sliced in thin strips; 1/2 cup mushrooms, sliced thin (I like crimini, or bella); 1 cup broccoli, chopped; 1 package udon noodles; 1/2 cup soy sauce; 2 tbsp. vegetable oil (Plus more for frying ); 2 tbsp. lemon juice; 2 tbsp. sugar; 1 tsp. garlic, minced; 1 tsp. ginger paste; 1/2-1/4 tsp. red pepper flakes; 1 tbsp. sesame seeds; 2 green onions, sliced thin