Ingredients

• 20 ounces zucchini (Note 1)
• 1 pound ground beef (Note 2)
• 1 (15-ounce) can tomato sauce (Note 3)
• 1 cup finely chopped onion (Note 4)
• 1½ cups shredded mozzarella cheese (Note 5)
• 1/2 cup finely grated parmesan cheese (Note 6)
• 1 tablespoon dried oregano
• 1½ teaspoons table salt
• 1/4 teaspoon ground cayenne (Note 7)

Instructions

1. Cook the Beef

Place the ground beef in a large, high-sided pan (Note 8) over medium-high heat. Break it apart as it cooks, continuing until the meat is fully browned and any released liquid has evaporated, about 7 to 8 minutes. If desired, drain excess grease, particularly if using beef that is less than 90% lean.

2. Prepare the Meat Sauce

Add the chopped onion to the pan with the cooked beef. Cook over medium-high heat, stirring occasionally, until the onion becomes soft and translucent, about a few minutes. Reduce the heat to medium and stir in the tomato sauce. Simmer, stirring frequently, for about 10 minutes, or until the sauce becomes thick enough to cling to the meat and onions (important for controlling moisture; see Note 9). Stir in the oregano, salt, and cayenne, mixing well for about 1 minute. Remove from the heat.

3. Prepare the Oven and Zucchini

Position an oven rack in the lower half of the oven and preheat to 375°F. Trim both ends from each zucchini. Stand each zucchini upright on a flat end and carefully slice lengthwise into strips about 1/8 to 1/4 inch thick (Note 10).

4. Assemble the Lasagna

Arrange one-third of the zucchini slices across the bottom of an 8×8-inch baking dish, overlapping them slightly. Spread half of the meat sauce evenly over the zucchini, then sprinkle with 1/2 cup mozzarella. Repeat with another layer of zucchini, the remaining meat sauce, and another 1/2 cup mozzarella. Finish with the remaining zucchini slices, then top with the last 1/2 cup mozzarella and the 1/2 cup Parmesan. Gently shake the baking dish so the cheese settles into the layers (see Note 11 for make-ahead instructions).

5. Bake and Serve

Bake uncovered at 375°F for about 45 minutes, or until the top is beautifully golden brown (Note 12). Allow the lasagna to cool for 15 minutes before slicing so the layers can firm up and the bubbling settles. Serve (Note 13) and refrigerate or freeze any leftovers (Note 14).

Recipe Notes

Note 1: Zucchini You'll need about 2 large or 3 medium zucchini. There's no need to peel them or remove the seeds. Since the sauce is cooked until very thick, pre-salting the zucchini isn't necessary (see Note 9). Note 2: Ground Beef Extra-lean ground beef (around 95% lean) works best to minimize grease. If your beef contains more fat, simply drain the excess after browning. Ground turkey, Italian sausage, or your favorite plant-based ground meat also work well. Note 3: Tomato Sauce Use 15 ounces (about 1¾ cups) of tomato sauce or tomato puree. Avoid thinner tomato products like diced or crushed tomatoes, which can make the finished lasagna watery. If using pasta sauce, the simmering time may need slight adjustment depending on its consistency. Note 4: Onion One small yellow onion, finely chopped, equals approximately 1 cup. Note 5: Mozzarella Cheese Use about 5 ounces of shredded low-moisture part-skim mozzarella. Pre-shredded cheese browns nicely, though cheddar, Monterey Jack, ricotta, cottage cheese, or vegan cheese have all been used successfully. Note 6: Parmesan Cheese Use finely grated Parmesan with a sandy, powder-like texture rather than shredded Parmesan. Note 7: Cayenne Pepper The small amount of cayenne enhances the overall flavor without making the dish spicy. Increase the amount or add red pepper flakes if you'd like more heat. Note 8: Pan Choose a pan large enough to hold the beef, onions, and tomato sauce together. A 10-inch skillet with tall sides works well. No oil or preheating is needed since the beef releases its own fat during cooking. Note 9: Keeping the Lasagna from Becoming Watery Instead of salting or grilling the zucchini beforehand, this recipe relies on simmering the tomato sauce until it's especially thick. During baking, the zucchini releases moisture, which is absorbed by the hearty sauce, creating well-defined layers without excess liquid. Note 10: Slicing the Zucchini Aim for slices between 1/8 and 1/4 inch thick, but don't worry if they're not perfectly even. A mandoline, vegetable peeler, or cheese slicer can make the job easier. Once sliced, the zucchini can be layered immediately. Note 11: Make-Ahead Tips The assembled, unbaked lasagna can be tightly covered and refrigerated or frozen. If baking directly from the refrigerator, plan for about 50 minutes of baking time instead of 45 minutes. Alternatively, bake the lasagna completely, refrigerate it, and reheat in the oven until warmed through before serving. Note 12: Baking Tips Check the lasagna after about 30 minutes. The cheese can brown quickly, so if the top reaches your desired color before the casserole is fully cooked, loosely tent it with foil. Note 13: Serving Suggestions Pair this lasagna with low-carb favorites like roasted artichokes with balsamic dip, garlic mushrooms, or creamy spinach for a complete meal. Note 14: Storing Leftovers Store cooled leftovers covered in the refrigerator or freezer. Reheat individual portions in the microwave or warm larger portions in the oven until heated through. Note 15: Nutrition Information Nutrition estimates assume all of the rendered fat from the beef remains in the dish. Draining the grease will reduce the overall fat and calorie content. Note 16: Doubling the Recipe To make a larger batch, simply double all ingredients. Assemble everything in a 9×13-inch baking dish and increase the baking time as needed until the center is hot and the top is golden brown. Nutrition Calories: 470kcal | Carbohydrates: 12.5g | Protein: 46g | Fat: 25g | Saturated Fat: 12g |
Cholesterol: 128mg | Sodium: 1260mg | Fiber: 4g | Sugar: 7.5g | Vitamin A: 22% DV | Vitamin C: 48% DV | Calcium: 45% DV | Iron: 24% DV | Net Carbs: 8.5g