Makes: 8 servings at $1.94 each. Prep: 10 minutes. Slow Cook: on high heat for 5 1/2 hours.
In 5- to 5-1/2-quart slow cooker, layer the chopped onion, pork roast and sweet peppers. In a medium-size bowl, stir together the tomatoes, cumin, garlic salt, oregano and cayenne pepper. Pour evenly over the mixture in the slow cooker. Add chiles and corn.
Cover slow cooker; cook on high heat for 5 hours. Remove pork roast to cutting board; keep warm.
Remove 1 1/2 cups liquid from pot and discard. Stir the tomato paste into the vegetable mixture in the slow cooker. Cover; cook for another 30 minutes.
Cut the pork roast into slices. Shred the slices using 2 forks to pull the meat apart. Add the shredded pork to mixture in the slow cooker; heat through.
To serve, wrap the pork mixture in the warmed corn tortillas, dividing the mixture equally among the tortillas. Garnish each serving with fresh cilantro leaves and sour cream, if desired.