Step 1

Puree the tomatoes, onions, garlic, chipotle and adobo sauce in a food processor until completely smooth.

Step 2

Heat the oil in a large Dutch oven or pot over medium-high heat until nearly smoking. Add the pork in a single layer, season with 1 teaspoon salt and 1/2 teaspoon pepper and cook, undisturbed, until beginning to brown, about 2 minutes. Turn the pieces and cook until brown, about 1 minute more. Dust the meat with the chili powder, and add the tomato puree, sweet potatoes, chicken broth, 1/4 teaspoon salt and a few grinds of pepper. Bring to a boil, reduce the heat to medium, cover and gently simmer until the meat is cooked through and the potatoes are tender, about 15 minutes.

Step 3

Meanwhile, prepare the toppings: Chop the jalapenos, and whisk together with the yogurt in a small bowl. Shred the cabbage, cut the avocado into chunks and cut the lime into wedges.

Step 4

Ladle the stew into large, deep bowls. Top with the yogurt mixture, garnish with the cabbage, avocado, lime and cilantro and serve with the tortillas.