Heat the olive oil in a large lided pot. Add the onion, garlic and chilli and fry, stirring, for 4 minutes.
Add the chopped tomatoes and stock and bring to the boil. Add the sugar and salt.
Add the pasta and once it softens slightly press it down to that it is submerged in the sauce.
Cover the pot and simmer for about 10 minutes (usually +2 minutes to whatever the optimum pasta cooking time is), occasionally stirring to make sure nothing sticks.
Once the pasta is cooked al dente, add lemon juice and crab meat and toss to combine.
Add the lemon zest, check the seasoning and add pepper and salt, if needed.
Serve sprinkled with the parsley, with a little grated cheese if you like.
Video
Notes
If you wish to double the recipe to serve 4, make sure the pot is large enough to accommodate the pasta and sauce and stir frequently to avoid it sticking.