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.
Dry the chicken thighs with paper towels, season well with salt and pepper on both sides and lightly dust with flour.
Heat 1 tablespoon of olive oil in a large skillet over a medium-high heat and place the chicken thighs, smooth side down. Cook for 7 minutes (turn heat down if browning too fast) then flip and cook for a further 5 minutes or until cooked through. Set aside, loosely wrapped in aluminium foil.
Feel free to cook the chicken however you prefer, as whole thighs or in bite size pieces.
In the same pan cook chorizo for 3 - 4 minutes or until lightly golden on each side.
Add the red onion and a big pinch of salt and continue cooking for 3 minutes until onion softens. Turn heat down if onion is browning.
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 2-3 separate lots, mixing and letting each addition melt in before adding the next.
Add the lemon juice and whisk in quickly.
Add your cooked pasta and spinach in, mix and let it gently bubble away for 1 - 2 minutes so the sauce thickens and clings to the pasta and the spinach wilts. Season to taste.