Heat the olive oil in a skillet over medium heat. Stir in the red bell pepper, red onion, and garlic, and cook 5 minutes, until tender. Mix in tomatoes, beans, potato, vegetable stock, water, Worcestershire sauce, and oregano. Bring to a boil, reduce heat to low, and simmer 30 minutes, until potato is tender.

Stir macaroni into the stew, and continue cooking 8 to 10 minutes, until al dente. Top with Cheddar cheese to serve.