Prep the oven and pan. Heat the oven to 400°F (200°C). Lightly grease a large baking dish so the zucchini don’t stick.

Hollow the zucchini. Trim the ends and slice each zucchini lengthwise. Use a spoon to scoop out the centers, leaving about 1/4 inch border so the boats hold their shape. Reserve about half the scooped zucchini flesh, finely chop it, and set aside.

Par-bake the boats. Arrange zucchini cut side up in the dish. Sprinkle with a pinch of salt and brush with a little olive oil. Bake for 10 minutes to soften slightly while you make the filling.

Sauté aromatics. Warm olive oil in a large skillet over medium heat. Add onion and cook until translucent, 3–4 minutes. Stir in garlic and the chopped zucchini flesh; cook 2 minutes more.

Brown the meat. Add ground turkey. Cook, breaking it up, until no longer pink, about 5–7 minutes. Drain excess fat if needed.

Season the filling. Stir in taco seasoning, salt, and pepper. Add tomato sauce, black beans, and corn. Simmer 2–3 minutes to thicken slightly. Taste and adjust seasoning. The mixture should be well-seasoned and a little saucy, not watery.

Fill the boats. Spoon the taco mixture into each par-baked zucchini shell, mounding it slightly.

Add cheese and bake. Sprinkle the tops with shredded cheese. Bake 10–12 minutes, until the zucchini are tender and the cheese is melted and bubbly.

Finish with toppings. Let cool a few minutes. Add fresh toppings like tomatoes, cilantro, green onions, avocado, and jalapeño. Squeeze lime over the top for brightness.

Serve. Plate with a dollop of Greek yogurt or light sour cream if you like. Enjoy while warm.