Brazilian Shrimp Soup

1 onion , chopped

1 green bell pepper , chopped

3 cloves garlic , minced

3/4 cup long-grain rice

1/4 teaspoon red- pepper flakes

1 3/4 teaspoons salt

1 3/4 cups canned crushed tomato es in thick puree (from one 15-ounce can)

5 cups water

1 cup canned unsweetened coconut milk

1 1/2 pounds medium shrimp , shelled and cut in half horizontally

1/4 teaspoon fresh-ground black pepper

1 tablespoon lemon juice

1/2 cup chopped fresh parsley or cilantro