Melt the butter and sauté the onions and celery until soft and translucent. Season well with salt and freshly ground black pepper.
Add the crushed garlic cloves, tomato paste, green chillies, oregano and cumin. Sauté, stirring, for about 2 minutes.
Add 2 cups of stock to the pot, then use an immersion blender to partially blend the mixture. You’re aiming for a chunky texture, so leave some pieces intact. If you prefer a completely smooth base, go ahead and blend it all the way.
Once the soup base is blended, add the tripe, carrots, corn, bay leaf and rest of the stock to the pot.
Bring to the boil, then reduce the heat to low and let the soup simmer for about 20 minutes until the carrots are soft.
Serve with some lime wedges, corn tortillas, and the hot sauce from the recipe below.