Spicy Spanish Sausage Supper

½ cup chopped green bell pepper

⅓ cup chopped celery

¼ cup chopped onion

1 tablespoon vegetable oil

1 pound smoked sausage

sliced

2 cups water

1 (10 ounce) can diced tomatoes with green chile peppers

1 (6.8 ounce) package Spanish-style rice mix

¼ cup sliced stuffed green olives

⅛ teaspoon ground black pepper