Combine iceberg, onions and tomatoes in a bowl then arrange on large cutting board or mound on a very large platter. Set aside.
In a bowl, combine all dressing ingredients except oil. While whisking, add the oil in slow stream to emulsify dressing. Transfer to a pitcher, squeeze bottle or gravy boat, and set aside.
In a large skillet over medium-high heat, brown ground beef in 2 tablespoons oil and season with salt, pepper, chili powder, 1 tablespoon cumin and coriander. Add onions, jalapeños and garlic, and soften 5 minutes. Add stock or beer and let it absorb.
Preheat oven to 400°F. Arrange chips on baking sheet and top with cheese. Bake to melt cheese and toast chips, 6-7 minutes.
For the avocado crèma, in a food processor, combine the avocado, salt, sour cream, juice of a lime, and a splash of water. Puree and transfer to bowl or squeeze bottle, rinse processor, return to base.
For the taco sauce, combine tomatoes with green chilies, vinegar, 1 teaspoon cumin, reserved chopped onion, about 2 tablespoons cilantro leaves, 1 teaspoon granulated garlic and salt to taste. Transfer to bowl.
To assemble salad, pour some dressing lightly over greens (reserve the rest to pass at table). Top the lettuce with warm cheesy chips then the beef taco topping. Garnish beef with dollops of avocado crema. Drizzle taco sauce across the nachos and sprinkle with sliced pickled jalapeño peppers and cilantro leaves to garnish.