Prep the zucchini: Preheat the oven to 400°F (200°C). Slice each zucchini in half lengthwise. Use a spoon to scoop out the center, leaving about 1/4 inch border to create a “boat.” Reserve about half of the scooped zucchini, finely chop it, and set aside.

Season and par-bake: Place zucchini halves cut side up on a baking sheet. Drizzle with 1 tablespoon olive oil and sprinkle with salt and pepper. Bake for 10 minutes to soften slightly. Remove and set aside.

Cook the filling: Heat remaining olive oil in a large skillet over medium. Add onion and cook 3–4 minutes until soft. Stir in garlic and cook 30 seconds. Add the ground protein, breaking it up with a spoon. Cook until browned and no longer pink, about 5–7 minutes.

Add veggies and spices: Stir in the chopped zucchini you reserved, plus any optional mushrooms or peppers. Cook 2–3 minutes until most moisture cooks off. Season with Italian seasoning, paprika, crushed red pepper (if using), salt, and pepper.

Build the sauce: Pour in the low-sugar marinara. Simmer 2–3 minutes to thicken slightly. Taste and adjust seasoning. If you want a denser filling, stir in almond flour or crushed pork rinds now.

Stuff the boats: Spoon the filling evenly into the par-baked zucchini shells. Top with mozzarella and sprinkle Parmesan over the top.

Bake and broil: Return to the oven for 12–15 minutes, until the zucchini is tender and the cheese is melted. Broil for 1–2 minutes at the end for a golden top. Watch closely to avoid burning.

Finish and serve: Let cool for a couple of minutes. Garnish with fresh parsley or basil. Serve warm with a crisp salad or roasted broccoli.