Before starting, preheat the oven to 450°F. Wash and dry all produce. Cut zucchini into 1/4-inch rounds. Roughly chop spinach.

Add zucchini, half the Italian Seasoning and 1 tbsp oil (dbl for 4 ppl) to an unlined baking sheet. Season with salt and pepper, then toss to coat. Roast in the middle of the oven until tender-crisp, 8-10 min. (NOTE: Zucchini will continue to cook in step 5.)

While zucchini roasts, heat a large oven-proof pan over medium-high heat. When hot, add 1/2 tbsp oil (dbl for 4 ppl), then beef. Cook, breaking up beef into smaller pieces, until no pink remains, 4-5 min.** Carefully drain and discard excess fat. Add remaining Italian Seasoning. Cook, stirring often, until fragrant, 1 min.

Reduce heat to medium, then add crushed tomatoes to the pan with beef. Cook, stirring occasionally, until sauce thickens slightly, 6-8 min. Add spinach and stir until wilted, 1-2 min. Season with salt and pepper. Remove the pan from heat, then transfer sauce to a large bowl.

Pat roasted zucchini slices dry with paper towels. Spread a third of the sauce across the bottom of the same oven-proof pan. (NOTE: For 4 ppl, assemble in a 9x13-inch baking dish.) Sprinkle a third of the cheese over sauce, then top with half the zucchini. Repeat layers, ending with cheese. Bake in the middle of the oven until cheese melts and skillet is warmed through, 6-8 min.

Let beef and zucchini skillet stand for at least 5 min before serving. Divide between plates. Tear parsley over top.