Step 1

In a medium (4-quart) pot over medium-high heat, heat the oil until shimmering. Add the ground beef and onion, and cook, stirring occasionally and breaking up the meat into small pieces with a wooden spoon, until the meat is no longer pink and the onion softens, about 5 minutes.

Step 2

Add the mushrooms and cook, stirring occasionally, until they have released their water and it evaporates, about 3 minutes. Add the garlic and cook, stirring, until aromatic, about 1 minute more.

Step 3

Add the zucchini, broccoli, basil, oregano, salt, black pepper and crushed red pepper flakes, if using, and cook, stirring occasionally, until the vegetables have softened slightly, about 3 minutes.

Step 4

Add the broth, tomato sauce and diced tomatoes, with their juices, increase the heat to high and bring to a boil. Stir in the macaroni, return to a boil, then reduce the heat to medium. Cook, uncovered and stirring occasionally, until the macaroni is just tender, about 8 minutes. Taste, and season with additional salt and crushed red pepper flakes, if desired. Serve family-style or divide among individual shallow bowls.