Drain the canned jackfruit, and rinse it very well to remove any brine. Use your fingers to "shred" the jackfruit into pieces that resemble shredded meat. Rinse the jackfruit again, then set it aside.
Heat the olive oil in a large skillet over medium heat, and saute the onion until it starts to soften, about 5 minutes.
Add the cumin, chili powder, and garlic to the skillet and stir briefly, just until the onions are coated in the spices. Add the jackfruit to the skillet and stir again. Add a splash of water to the pan if the seasonings are sticking to the bottom.
In a small bowl, stir together the tomato paste, mape syrup, lime juice, and salt. Add about 2 tablespoons of water, or more as needed, to help thin it out into a sauce that resembles the texture of ketchup. (If your tomato paste includes salt in the ingredients, leave out the salt and add it to taste later.)
Add the sauce to the skillet and stir well to coat the jackfruit. Cook and stir until everything is heated through, and adjust any seasonings to taste. Depending on how well you rinsed your jackfruit, you may want to add a little more salt, or another splash of maple syrup to help balance out the acidity. Serve warm, in your favorite taco shells and with your favorite toppings.
Leftover jackfruit taco meat should keep well in an airtight container for up to a week in the fridge.
This recipe is easy to double if you're serving more than 2 adults! We usually get about 6 generously-filled tacos from this recipe.