In a large frypan cook beef mince. Drain excess grease.
In a separate pan saute the onion, garlic and green capsicum in olive oil until tender. Add the cooked beef mince, tomatoes, water, Italian seasoning and ground black pepper. Add salt, if desired. Simmer for an hour.
As simmering time nears, in a large pot cook spaghetti until al dente. Drain.
In a large bowl, toss drained spaghetti with tomato paste. Add cooked sauce; mix well.