Step 1

In a small heatproof bowl or measuring cup, soak mushrooms in boiling water until fully softened, about 20 minutes. Using a slotted spoon, remove mushrooms from soaking liquid and squeeze out excess moisture back into the bowl or measuring cup. Reserve rehydrated mushrooms and 1/4 cup (60ml) soaking liquid, making sure to dispose of any grit that has settled at the bottom.

Step 2

In a 5-quart pot, combine 1/4 cup (60ml) olive oil, garlic, pepper flakes, and 1 tablespoon minced parsley. Set over medium heat and cook, stirring frequently, until very fragrant and garlic is just beginning to turn the lightest shade of gold, about 3 minutes.

Step 3

Add mushrooms and cook, stirring, until lightly sautéed and fragrant, about 1 minute.

Step 4

Add reserved 1/4 cup (60ml) mushroom soaking liquid, tomatoes, and 2 tablespoons (30ml) reserved tuna oil (if your tuna doesn't have that much oil, just add as much as it does), and bring to a simmer. Season with salt.

Step 5

In a pot of salted, boiling water, cook spaghetti, stirring frequently, until just shy of al dente, about 1 minute less than package recommends. While spaghetti is cooking, flake tuna into pasta sauce.

Step 6

Using tongs, transfer spaghetti directly into simmering sauce along with 1/4 cup (60ml) pasta cooking water, stirring to combine. Cook, stirring, until pasta is al dente and sauce has thickened, so it coats noodles and isn't watery, about 3 minutes. Add remaining 1/4 cup minced parsley and 1/4 cup (60ml) olive oil, stirring vigorously to combine. If sauce is too thick, add more olive oil or pasta water, 1 tablespoon at a time, stirring well between additions, until desired sauce consistency is reached. Taste for seasoning, adding more salt if necessary.

Step 7

Transfer to warmed plates and sprinkle with minced parsley. Serve right away.