Combine the ground beef and chorizo in a bowl and sprinkle with the smoked paprika, 1 teaspoon salt and 1 teaspoon pepper. In another bowl, combine the evaporated milk, panko and egg, and then add to the meat mixture. Combine well with your hands and form into 4 patties. Set aside.
In a small bowl, combine the mayonnaise, lime juice, orange juice and garlic. Season with salt and pepper. Set aside.
In a small saucepan, combine the guava paste with 3 tablespoons water. Cook down over low heat until reduced slightly. Add the cider vinegar; cook 2 minutes more.
In a medium saute pan over medium-low heat, cook the onions in the butter, stirring occasionally, until caramelized, about 45 minutes. Add the onions and ketchup to the guava mixture. Season with salt and pepper.
Preheat a grill pan over medium-high heat. Cook the patties until crispy on both sides but soft in the middle, turning once, 4 minutes per side. Grill the cut sides of the buns until grill-marked, about 1 minute.
Grate the potatoes on the large holes of a box grater or in a food processor fitted with the shredding disk. Heat 1 inch of olive oil in a deep skillet and fry the grated potatoes until crispy, 4 to 5 minutes. Toss with smoked paprika and salt.
Spread the bottom halves of the buns with a little of the "mojo mayonnaise," top with the patties and then cover with the bun tops. Add the crispy fries on the side and top with the guava ketchup.
This recipe was created by a contestant during a cooking competition. It has not been tested for home use.