Shape ground sirloin into 4 oval pat ties about 1 inch thick.
In skillet cook patties till rare, about 5 minutes per side.
Place each on a well buttered seasoned steak plank; sprinkle with salt and pepper.
Place fluffy potatoes in pastry bag; pipe onto plank to form border 1 inch larger than patty.
Place 2 planks under broiler, 4 inches from heat; broil till potatoes brown lightly, about 4 minutes.
Repeat with remaining planks.
Arrange carrots and peas within potato border; sprinkle with snipped parsley.