Melt butter in a large pot over medium heat. Cook onions in butter until they begin to soften, about 10 minutes; stir in garlic and cook for one minute. Add mince and cook until for 10 to 15 minutes, stirring occasionally to break up lumps. Stir in the tomato puree, tomato juice, water and chickpeas. Season with salt, pepper, mustard, dill, coriander, chilli paste and lemon juice. Bring to the boil, then reduce heat to low. Simmer uncovered 30 minutes.
Increase heat and bring mixture to a low boil; add fettuccine, reduce heat to medium-low and cook until fettuccine is tender, about 10 minutes. Adjust seasonings adding more chilli paste, salt or lemon juice as desired. If soup seems too thick, thin with a little water.