Set a large pot or Dutch oven over medium-high heat. Add oil and swirl to coat the pot. Add the mushrooms, sprinkle with salt and pepper, and cook, stirring occasionally, for 4 to 5 minutes, or until the mushrooms give off liquid and it completely evaporates. Add ½ tablespoon butter to the pot and stir and cook until the mushrooms are tender and browned, a couple minutes more.

Remove the mushrooms to a bowl, reduce the heat to medium, add a few drops of extra-virgin olive oil to the pot, and saute the garlic for a minute or two until just fragrant and very light golden brown. Add the ground beef (or Italian sausage) and increase the heat to medium/medium high. Cook until no longer pink, breaking apart and stirring as the meat cooks. When the meat is almost done, stir in the chopped pepperoni and continue to cook until the meat is completely browned. Drain the grease from the pot and, if using ground beef, season to taste with salt and pepper (Italian sausage probably won’t need additional seasoning).

Turn off the heat under the pot (to reduce splattering while adding remaining ingredients). To the pot of cooked beef/sausage, add the tomato purée, tomato paste, honey, dried basil, dried oregano, dried parsley, dried thyme, crushed fennel seeds, garlic powder, onion powder, 1 teaspoon salt, and crushed red pepper flakes. Pour in the beef broth and the black olives (if using) and stir to combine. Add the broken fettuccine to the pot and stir; push down until completely submerged in the sauce. Bring to a boil, stir, and then reduce to a simmer. Cover and cook for 10 to 12 minutes, stirring occasionally, until the pasta is al dente (lower the heat if the pasta is sticking and try to keep the pasta submerged in the sauce). If the liquid evaporates before the pasta is done, stir in an additional ½ cup beef broth. While the pasta is cooking, preheat the broiler to high.

Once the pasta is done, stir the sautéed mushrooms into the pot and adjust the salt and pepper, to taste. Top with shredded mozzarella cheese, whole pepperoni slices, and Parmesan cheese. Broil for 2 to 4 minutes, watching the entire time, until the cheese is melted, bubbly, and just starting to brown around the edges. Garnish with fresh chopped parsley or a chiffonade of basil.