Blanch scallion in boiling water for 30 seconds. Drain. Whish beer soy and sugar together. Set aside.
Trimi beef to 4-5 inch slices. Season with salt and pepper.
On the bottom edge of the slice of beef, lay a cluster of cucumber and scallions. Roll tightly and secure with toothpick. Brush rolls with reserved beer sauce. Let stand 10 minutes.
Heat oil on med-hi. Add rolls to pan and turn and brown on all sides. (5 mins). Transfer to a plate.
To the skillet, pour the beer soy sauce mixure. Simmer until syrup-like consistency. (2 min)
Remove toothpicks from rools, and slice into 1/4's. Serve with white rice garnished with cilantro, and pour sauce over the rolls.