Preheat oven to 325F. Season meat with lots of salt.
Add 2 tablespoons of olive oil to large pot over medium heat. Add the meat in one layer once oil is hot. Sear on both sides. Remove from heat and set aside.
Combine cilantro leaves, your serrano peppers that have been deseeded and chopped, and 1/4 cup of stock. Blend until smooth.
Cook your onions and then add garlic and cook until fragrant. Stir in cumin, pepper, paprika and pinch of salt.
Add back in the meat and its juice along with the cilantro mixture and remaining 1 1/4 cup of stock.
Cover the pot with lid and transfer to the oven. Simmer for 1 ½ - 2 hours or until tender, adding stock as needed. Stir in potatoes and cook for an additional 30 minutes, until potatoes are tender.
Salt and pepper to taste. Serve over rice and garnish with cilantro.