Vietnamese Garlic Beef over Lettuce

Ingredients

• 1 pound lean beef like top round or flank steak trimmed and thinly sliced across the grain
• 1 tablespoon fish sauce
• 5 tablespoons olive oil
• Salt
• pepper
• ¼ teaspoon sugar
• ¼ teaspoon red chile flakes
• 1 small sweet onion thinly sliced (soak in water if too strong)
• 5 large garlic cloves coarsely chopped
• 2 teaspoons apple cider vinegar
• 1 teaspoon Dijon
• 1 large tomato cut into chunks
• Salad greens and cilantro for four
• White rice