Preheat your oven to 375°F (190°C). Place the hot dog buns on a baking tray and cover them lightly with foil to maintain softness. Warm them in the oven for 5–7 minutes while you prepare the other components.

Bring a medium sized pot of water to a gentle boil. Add the hot dogs and cook for 5 minutes or until heated through. Avoid overcooking to retain their juicy texture. Remove the hot dogs from the water and set aside on a plate.

In a bowl, mash the avocados until smooth but slightly chunky. Add lime juice, a pinch of salt, and pepper. Mix well to enhance the creamy flavour while keeping the authentic texture of the topping.

Heat 1 tbsp olive oil in a small skillet over medium heat. Sauté the finely chopped onion (if using) until soft and translucent, about 3–4 minutes. This step adds depth of flavour but is optional based on personal preference.

Combine the chopped tomato with a small pinch of salt in a separate bowl. Let it sit for 5 minutes to release some of the natural juices, enhancing its freshness when layered onto the completo.

Assemble the base by spreading mayonnaise generously inside each warm bun. Layer in the sauerkraut (if using) for added tanginess and texture.

Place one hot dog in each bun. Top with mashed avocado, chopped tomato, and sautéed onions (if used). Drizzle ketchup and mustard over the toppings in a zigzag pattern for a visually appealing presentation.

Serve the completos immediately while warm. Pair them with a side of crispy fries or a light salad for a complete meal. To elevate the experience, offer additional condiments like chili sauce or more lime wedges for customization. Encourage diners to enjoy the dish with a napkin ready, it’s meant to be a deliciously messy affair!