Preheat oven to 350 degrees F (175 degrees C). Line a 9x11-inch baking pan with aluminum foil. Arrange bell pepper halves in the baking pan.
Bring water and bulgur to a boil in a small saucepan. Cover and simmer until bulgur is tender, 12 to 15 minutes. Drain excess water.
Combine bulgur, tomato sauce, arugula, corn kernels, garbanzo beans, lima beans, black beans, kidney beans, salt, paprika, basil, and oregano in a large bowl. Fill each bell pepper half generously with bulgur mixture.
Bake in the preheated oven until bubbly and hot, 25 to 30 minutes.