Boil your pasta according to package instructions, I tend to undercook by a minute so it can bubble in the sauce at the end. Reserve a cup of pasta water before draining.
While your pasta is boiling heat a large fry pan or skillet over a medium-high heat and cook chorizo for 3 minutes or until lightly golden. You won't need to use any oil as the chorizo will release some but add a drizzle if you need.
Add the red onion and a big pinch of salt and continue cooking for 3 - 5 minutes until onion softens. Turn heat down if onion is coloring.
Add the garlic and cook for a further 30 seconds.
Add the tomato paste and paprika and cook down for 2 minutes. All these individual additions are necessary for flavor layering, I promise!
Add the cream and mix well, bring to a very gentle simmer. It will look dodgy to begin with but will come together. You might need to turn the heat down, it should never be boiling.
Add ⅓ cup pasta water and mix in well, bringing back to a gentle simmer.
Push the chorizo to one side of the pan and add the grated parmesan in two separate lots, mixing and letting the first lot melt in before adding the second.
Add the lemon juice and whisk in quickly.
Add your cooked pasta in, mix and let it gently bubble away for 1 - 2 minutes so the sauce thickens and clings to the pasta.
Toss the parsley through right before serving and enjoy!
Check out the video below to see the sauce come together!