Season flank steak strips with salt and pepper, then toss with cornstarch. Shake off excess.
Fill a large frying pan with enough oil to cover the bottom by 1/4 to 1/2-inch. Heat the oil to 365 degrees F. First add noodles to oil and let cook for 3 to 4 minutes. Take out noodles and then, working in batches, fry the steak. Do not crowd pan. Drain on paper towels. Set aside.
For the sauce: Heat the oil in a medium frying pan over medium heat and cook the garlic until fragrant; do not let the garlic brown. Add orange marmalade, 1/2 cup beef broth, soy sauce, and chiles. Bring to a boil and reduce to a simmer for 5 minutes. In a small bowl, stir cornstarch into remaining 1/2 cup beef broth. Stir cornstarch mixture into simmering sauce. Return to a simmer for 3 to 4 minutes until sauce thickens.
Make a bed of the frisee lettuce on a platter. Put the crispy noodles on top and then the beef. Pour sauce over beef and serve.