***Skip this step if using canned black-eyed peas. Soak the black-eyed peas in a large pot of water overnight, or for at least 8 hours. Rinse thoroughly. Boil the black-eyed peas in a pot of salted water until they are tender, about 30 minutes. Drain and set aside.
Preheat oven to 325 degrees.
Melt the butter in a large skillet over medium heat. Add the onions and cook for 3 minutes. Stir in the sausage and garlic and cook for 5 minutes. Add the kale, season with salt and pepper, and cook for 3 minutes. Stir in the cooked black-eyed peas and tomatoes, and cook for 1 minute longer. Add the cayenne pepper. Season with salt and pepper, to taste.
Pour 1/3 of the black-eyed pea mixture in the bottom of an 8 x 8 baking dish and top with 2 ounces of cheese. Repeat two more times, ending with the cheese.
Bake in a preheated oven uncovered for 10 minutes. Allow it to sit for 5 minutes before serving.