In a bowl, crumble 250 grams of tempeh into small pieces.
Heat 2 tablespoons of oil in a pan over medium heat. Add 1 finely chopped onion, 2 minced garlic cloves, and 1 tablespoon of grated ginger. Sauté for 3-4 minutes until the onion is translucent.
Add the crumbled tempeh to the pan and cook for 5-7 minutes, stirring occasionally, until it turns golden brown.
In a small bowl, mix together 2 tablespoons of soy sauce, 1 tablespoon of hoisin sauce, 1 tablespoon of rice vinegar, and 1 teaspoon of sriracha sauce. Pour this sauce over the tempeh mixture and cook for another 2-3 minutes, allowing the flavors to meld.
Remove the pan from heat and stir in 2 finely chopped spring onions and 1/4 cup of chopped fresh coriander.
Wash and dry 8-10 large lettuce leaves (preferably iceberg or butter lettuce). Place a spoonful of the tempeh mixture onto each lettuce leaf and garnish with additional spring onions and coriander, if desired.