Step 1

Thinly slice 2 garlic cloves. Drain the oil from 1 (2-ounce) can anchovies. Grate until you have 1/4 cup Pecorino Romano or Parmesan cheese. Coarsely chop 1/4 cup fresh flat-leaf parsley or basil leaves.

Step 2

Heat 3 tablespoons olive oil in a large Dutch oven or straight-sided skillet or frying pan over medium heat until shimmering. Add the garlic, anchovies, and 1/2 to 1 tablespoon red pepper flakes, depending on your heat preference. Cook, stirring with a wooden spoon and breaking apart the anchovies, until fragrant but before the garlic browns, about 1 minute. Add 1/4 cup tomato paste and stir constantly until it becomes a deep red color, about 2 minutes.

Step 3

Add 1 (28-ounce) can crushed tomatoes and 2 1/2 cups water, and bring to a boil over medium-high heat. Stir in 1 pound penne pasta and adjust the heat to maintain an active simmer (bubbles breaking across the surface of the liquid). Simmer, stirring occasionally, until the pasta is al dente (about 2 minutes less than the package instructions), about 9 minutes total. If the pasta is undercooked at this point, add 2 tablespoons water at a time until done.

Step 4

Reduce the heat to low. Stir in 3 packed cups baby spinach a handful at a time until wilted. Taste and season with salt as needed (likely only a tiny amount and remember that you’re adding salty cheese soon). Garnish with the cheese and herbs.