"It's one of those dishes I always come back to for more. Best thing is, there is room to tweak it a bit to suit your style. The type of sausage you use will greatly affect the taste of the whole dish. I'm partial to Sicilian-style chicken sausage for this recipe. Garnish each bowl with Parmesan cheese."
Heat butter and oil in a large skillet over medium heat. Add onion and garlic; cook and stir until the onion starts to soften, about 2 minutes.
Increase heat to high and add pancetta to the skillet. Cook and stir until crispy, 3 to 5 minutes. Remove casings from the sausages; add sausage meat to skillet. Cook and stir until browned, 3 to 5 minutes. Pour in wine and scrape the bottom of the skillet.
Toss mushrooms into the skillet. Cook, stirring occasionally, until slightly softened, 5 to 10 minutes. Add tomatoes, basil, oregano, and salt. Stir to combine. Reduce heat to low; cover and simmer, stirring occasionally, until the sauce is thick, 1 to 2 hours.
Fill a large pot with salted water and bring to a rolling boil. Stir in orecchiette and return to a boil. Cook pasta uncovered, stirring occasionally, until tender yet firm to the bite, about 7 minutes. Reserve 1/2 cup of cooking water and drain without rinsing the pasta.
Stir spinach into the sauce in the skillet. Cook until wilted, about 1 minute. Toss pasta into the skillet and stir to combine everything. Stir until heated through, adding some reserved pasta water if the sauce seems too thick.