Cook the Pasta: Bring a large pot of generously salted water to a boil.
Add the spinach fettuccine and cook according to package directions until al dente.
Pan-Fry the Tofu: While the pasta cooks, heat the olive oil in a large skillet or pan over medium-high heat.
Add the cubed tofu and cook, tossing frequently, until golden brown and crisp on all sides.
Transfer the cooked tofu to a plate and set aside.
Sauté the Aromatics: Reduce the heat to medium. If the pan is dry, add another splash of olive oil.
Add the diced onions, minced garlic, and red pepper flakes.
Sauté for about 5 minutes, stirring often, until the onions are soft and fragrant.
Simmer the Sauce: Return the golden tofu to the skillet.
Pour in the tomato purée, salt, and a generous amount of freshly ground black pepper.
Stir everything together and bring to a gentle simmer.
Let it cook for 8-10 minutes, allowing the sauce to thicken and the flavors to meld.
Serve: Drain the cooked fettuccine well.
Divide the pasta among four serving plates. Spoon the hot tofu and tomato sauce generously over the top.
Garnish with fresh minced parsley and serve immediately.
Before draining your pasta, reserve about a cup of the starchy cooking water.
Add a few tablespoons to your tomato sauce as it simmers to help it thicken and cling beautifully to the fettuccine.
