How to Make It
Fill a stockpot with 6 quarts of water, cover and bring to a boil.
In a nonreactive skillet large enough to hold the pasta, combine the olive oil, tomato paste, garlic and 1 teaspoon salt. Cook over moderately low heat, stirring occasionally, until the garlic is golden, about 5 minutes. Remove from the heat.
Add 3 1/2 tablespoons kosher salt to the water and add the spaghetti. Cover partially until the water just returns to a boil, then uncover, stir the pasta and cook until al dente.
Drain the spaghetti, add it to the skillet and toss well. Add the parsley and basil and toss again. Transfer to plates, garnish with the scallions and serve immediately.