1.Place beans in a medium bowl, cover with water; stand overnight, drain.
2.Cook beans in a large saucepan of boiling water, uncovered, until tender; drain. Rinse under cold water; drain.
3.Meanwhile, cover chillies with the boiling water in a small heatproof bowl; stand for 20 minutes. Discard stalks from chillies. Blend or process chillies with soaking liquid until mixture is smooth.
4.Heat half the oil in a large saucepan over high heat; cook brown onion and garlic, stirring, for 3 minutes or until onion softens. Add chilli mixture, paste, tomato, the water, juice and sugar; bring to the boil. Remove from heat; blend or process mixture until smooth.
5.Return chilli mixture to pan; add beans, simmer, covered, for 20 minutes. Uncover; simmer for about 10 minutes or until sauce thickens. Season to taste.
6.Meanwhile, combine marjoram, paprika and the remaining oil in a large bowl; add beef, turn to coat in mixture, season. Cook beef on a heated oiled grill plate (or grill or barbecue) until browned both sides and cooked as desired. Cover beef; stand for 10 minutes, then slice thinly.
7.Meanwhile, heat tortillas according to directions on packet. Serve tortillas topped with chilli beans, red onion, lettuce, beef, coriander and sour cream.