Preheat the oven to 350°F (175°C). Arrange the halved cherry tomatoes on a parchment-lined baking sheet. Roast for about 12 minutes, until softened and slightly caramelized around the edges.

Meanwhile, bring a large pot of salted water to a boil. Cook the fettuccini according to the package directions until al dente. Drain and set aside, reserving a little pasta water.

Melt the butter in a large skillet over medium heat. Add the sliced mushrooms, spinach, and sun-dried tomatoes.

Sauté until the mushrooms are tender and the spinach has wilted, about 4–5 minutes.

Sprinkle the flour over the vegetables. Stir continuously for about 1 minute so the flour cooks without browning.

Slowly pour in the chicken or vegetable broth while whisking or stirring continuously to create a smooth sauce.

Add the heavy cream and Parmesan. Stir until the cheese melts and the sauce becomes smooth and creamy.

Reduce the heat to low and allow the sauce to simmer gently until it begins to thicken. If it becomes too thick, add a splash of cream, milk, broth, or reserved pasta water.

Blend the rustic Tuscan mushroom mixture briefly until mostly smooth, then stir it into the Creamy Tuscan Mushroom Sauce with Fettuccini. Simmer for another 2–3 minutes.

Add the cooked fettuccini and toss gently until every strand is coated in the creamy mushroom sauce.

Season with salt and freshly ground black pepper to taste. Top with the roasted cherry tomatoes and additional Parmesan before serving.