Put rinsed and chopped cilantro and spinach in the blender and process with one cup water. Reserve.
Heat the oil in a saucepan over high heat and the beef pieces and sauté until golden brown. Remove from pan and reserve.
Turn the heat to medium and add the onions, garlic and aji amarillo paste to the sauce pan; stir and let them cook until the onions are soft and translucent stirring often.
Pour in the cilantro mixture and stir constantly until the water evaporates by half. Add the beef back to the pot.
Add water enough to cover and simmer over low heat for 2 hours with the lid on. Check often and add more water if necessary.
When the meat is fork tender add the potatoes, green peas, carrots, salt and pepper to taste; cook uncovered for 15 or 20 minutes or until the vegetables are tender.
The stew is ready when the veggies are cooked and the juice is thickened.
This dish is usually served with rice and beans.