First, get the pineapple ready. Cut the pineapple in half. Cut off the end, then slice the sides off (you are just trying to get rid of the hard skin). Once the skin is off, cut slices of the pineapple into ¼ inch slices (thin enough to place insides a burger). Use your knife to cut out a circle in the middle of your pineapple slice to remove the hard core. You will need 4-5 slices.
Now place the thinly sliced sweet potatoes or yam in a bowl along with the thin pineapple. Coat with coconut oil and a sprinkle of salt. Place on a parchment lined baking sheet, baking sure not to overlap. Put in oven to bake for 10-12 minutes, flipping half way through. The pineapple way cook a bit quicker and you may need to remove it before the sweet potatoes.
While that is cooking, place the chorizo and ground beef in a bowl and mix well. Use the mixture to make 8 equal size balls. You could make 10 (to create 5 burgers) but they might not hold together as well. Flatten balls out into patties.
Then you'll want to make the avocado topping. Cut avocados in half, remove pits, and use a spoon to scoop out the avocado. Place in a food processor along the the lime, lemon, cayenne pepper, and a bit of salt and pepper. Puree until smooth.
Once the pineapple is done cooking, let cool then place on top of one of your patties, place the second patty on top and use your fingers to seal up the burger, pinching the edges a few times. The more you make sure it is closed up, the better they will stick together when you cook them. Repeat with all burgers. Salt both sides of your burgers.
Place a large skillet over medium-high heat. Add a couple tablespoons of bacon fat to the pan. Once the pan is extra hot, add the burgers to the pan, making sure not to crowd the pan so you get a nice crust on the burgers. Cook for 4-5 minutes per side.
Once burgers have cooked on both sides, place in the oven either in your skillet or on a baking sheet. Bake for 6-8 minutes.
When burgers on done, place on top of a stack of sweet potato slices, then top with the avocado puree.
Recipe by PaleOMG - Paleo Recipes at http://paleomg.com/pineapple-stuffed-chorizo-burgers/