Bring the pot of water to a boil with the 2 Tbsp of salt.
While the water is boiling, chop up the garlic finely, slice the chillies into thin slices and halve the cherry tomatoes.
Time to get cooking!
Add the spaghetti to the boiling water and cook for 8-10 until al dente, depending on the cooking instructions on the packet.
At the 6-minute mark, heat the olive oil in a large frying pan on medium heat and toss in the garlic, chillies, anchovies and tomatoes.
Stir and cook for 2 minutes.
Add the tuna and baby spinach and cook for a minute to heat through and for the spinach to wilt. Add a ladle of the pasta water and ¼ tsp salt and stir in.
When the spaghetti is done, drain and add to the tuna in the pan and stir thoroughly. Check seasoning and finish of with plenty of black pepper.
Squeeze some lemon juice all over and serve immediately.
Optional Breadcrumb Gremolata (wants to be made before the pasta above)
Heat the olive oil on medium-high heat and drop in the breadcrumbs.
Fry for 5 minutes until they take on a golden brown colour. Tip out onto a flat plate to cool. They will continue to brown slightly. While waiting...
Finely chop the garlic and parsley and place in a bowl.
Grate the lemon for its zest and add to the garlic and parsley and mix well. This is your gremolata.
When the breadcrumbs have cooled, add as much or as little of the gremolata as you like, starting with 1 tablespoon. Taste and add more if you like.
Sprinkle this all over your pasta and serve.
Leftover gremolata and breadcrumb gremolata can be kept in the fridge, tighly covered, for a day. Breadcrumbs can be kept for up to 3 days or frozen for up to 1 month.