Cut cherry tomatoes in half, chop arugula into bite-sized pieces, and slice bacon into 2cm strips.

Remove bones from mackerel, sprinkle with a pinch of salt, let sit for 10 minutes, and pat dry. Cut into bite-sized pieces.

Heat olive oil, minced garlic, and sliced chili in a pan. Add mackerel and bacon, and cook over medium heat until mackerel is flaky and cooked through.

Boil water in a pot, add salt and spaghetti, and cook 30 seconds less than the package instructions. Reserve pasta water and drain.

Add spaghetti, cherry tomatoes, lemon juice, salt, pepper, and pasta water to the pan. Mix well to combine.