Bring a large pot of salted water to a boil. The water should taste like the sea.
Peel and roughly chop the garlic clove.
Place the garlic with the olive oil in a sauce pan large enough to hold the pasta, and simmer over a low flame until the garlic begins to sizzle.
Add the tomatoes, stir and cover.
Cook for several minutes over a low flame stirring occasionally.
Add the chili pepper and anchovy fillets and cook covered for several more minutes.
Use a wooden spoon to smash the anchovy fillets so that they are fully amalgamated into the sauce.
If needed add pasta cooking water by the tablespoonful so the sauce does not dry out.
While the sauce is cooking put your spaghetti into the pot of boiling water and cook until al dente, or according to package instructions.
Mince the parsley.
When the spaghetti is done use a pasta claw to lift it out of the pot and place directly into the sauce pan with the tomato sauce.
Toss the sauce together until the spaghetti is covered.
Add half the parsley and toss again.
Place the pasta in a serving bowl and sprinkle with the remaining parsley.
If desired garnish with the additional anchovy fillets.