In a small mixing bowl, combine 1 tablespoon of the red curry paste with the cornstarch, salt, pepper and water. Stir to mix and thicken the mixture.
2 tablespoons red curry paste, 1 teaspoon corn starch, 1/2 teaspoon salt, 1/2 teaspoon pepper, 1 tablespoon water
Add the steak and mix so that the mixture completely covers the beef. Let stand for 5 minutes.
1 pound beef flank steak, cut into strips
In your skillet, add the vegetable oil and heat on medium until the oil is sizzling.
1 tablespoon vegetable or canola oil
Add the beef to the skillet in an even layer and cook on medium heat until brown, approximately 4 minutes. Flip the beef and cook for an additional 2-3 minutes or until just cooked through. If you cannot fit all the beef in a single layer, do it in batches. Once cooked, transfer to a plate for now.
In the same pan, add the remaining red curry paste, the fresh ginger and the fresh garlic. Fry for 2 minutes.
1 tablespoon fresh minced ginger, 1 teaspoon fresh minced garlic
Add the coconut milk and beef stock and bring to a boil, about 5 minutes.
1 cup coconut milk, 1 cup beef stock
Add the bell pepper, celery, carrots, broccoli and sugar snap peas. Reduce the heat to maintain a simmer and cook until the vegetables are tender crisp, about 10 minutes.
1 cup broccoli florets, 3/4 cup bell pepper, 3/4 cup carrots, 1 cup sugar snap peas, 1/2 cup celery
Return the beef to the pan and cook for a few minutes until the beef is warmed up.
Remove from heat and stir in the green onions and cilantro.
3/4 cup sliced green onions, 3 tablespoons fresh cilantro
Serve immediately over rice or noodles.