Place the drained beans in a large bowl and mash them slightly with a potato masher.
Add the beef, onion, garlic and spices, then salt &pepper. Combine well, then shape the mixture into 4 patties. Rest them till you're ready to cook.
Make the salsa – finely chop the tomatoes, onion, herbs, and jalapeno and put them in a bowl. Season with salt and pepper, add the oil and lime. Set aside.
Cut the buns in half and toast or grill them. Set aside.
Heat your grill, BBQ, griddle pan or frying pan.
Brush the burger patties with oil, then grill, griddle or pan-fry them on both sides to your liking (about 3-5 min on each side)
Optional: Put some sliced cheese on the top for the last minute, then put a lid or round metallic bowl over the patties to allow the cheese to melt.
Assemble the burgers: put a piece of lettuce on the bottom half of the bun, add some salsa, then the burger, then a pickled jalapeno and finally top with the other half of the bun. As a low-carb version serve the patties wrapped in a lettuce filled with salsa.