Slice the leek lengthwise in half then dice it up. Add it to a large bowl of cold water and allow the grit to drop to the bottom for a ew minutes. The leeks will float to the top.
Use both your hands and transfer the leeks to a large kitchen towel to drain.
In a large cast iron pot on low flame add a lug of olive oil. Add the leeks and a pinch of salt and sauté until wilted and they start to catch some color. Make sure not to burn them.
Add the carrots and half of the diced bell pepper and toss to coat. Cook for a few minutes then add the paprika and sea salt. Give everything a good stir.
Add the chicken to the pot and use a wooden spoon to stir well to coat all over in the paprika infused olive oil with leeks. Add the bay leaves and parsley sprigs then pour in enough water to come up the sides of the chicken but without covering it.
Bring the chicken stew to a gentle simmer and cover tightly with a lid. Allow the stew to simmer for 45 minutes.
After 45 minutes have passed add the remaining green bell pepper to the pot and continue cooking partially covered for another 10 minutes or so until the sauce has reduced to your liking and the chicken falls apart when stabbed with a fork. Add the green peas and cook an extra 2 to 3 minutes if using fresh peas. Adjust seasonings to your taste and remove from heat.
Add the tomatoes to the pot with the chicken and gently stir them between the chicken and under the sauce. Cover back with the lid and allow the stew to sit covered for a few minutes for the tomatoes to release their juices into the sauce. Serve hot over polenta and sprinkled with the chopped parsley.
While the chicken stew is simmering away, make the polenta.
Bring 10 cups of water to a rolling boil and season with the sea salt.
Whisk in the cornmeal into the boiling water until incorporated. Turn the flame to low and partially cover with a lid.
Simmer the polenta on low flame for about 1 hour until cooked through and thickened. Make sure to stir well with a wooden spoon every 15 minutes or so.
Once the polenta is cooked remove it from heat and stir in the cold butter until melted and incorporated. Stir in the milk or cream and serve with the chicken stew on top.