Boston Lettuce with Beef and Eggs

Ingredients

• 1 head Boston lettuce (or 2 bibb or butter lettuce)
  
• 2 hard boiled eggs, sliced
  
• ¹/₂ pound cooked beef or roast beef, diced or chopped
  
• 2 green onions, white and green parts, sliced
  
• 1 tablespoon oil
  
• 2 tablespoons lemon juice or white vinegar
  
• salt and freshly ground black pepper to taste