Preheat your oven to 400 degrees F. Slice each zucchini in half, lengthwise. Using a spoon, scoop out the zucchini flesh to create a boat. Save the flesh and freeze - then sneak them into your kids smoothies!
Line up your zucchinis onto a baking sheet, or in a casserole dish - I like to line my baking sheet with parchment paper. Sprinkle the zucchini boats with a little salt. Pre-cook zucchini in the oven for 10-15 minutes or until the flesh starts to get tender. If you find that any moisture is collecting at the bottom of the boats, just blot carefully with a paper towel or clean kitchen towel.
Meanwhile, mix salt free taco seasoning and prepare taco meat.
Skillet: brown meat over medium heat, then add in seasoning mix, sauce, salt, and water/broth. Stir meat mixture until slightly thickened.
Instant Pot: Spray Instant Pot with cooking oil spray and set to sauté. When IP is hot, add in meat and brown until cooked almost through. Add in seasoning mix, sauce, salt, and water/broth. Stir meat mixture and cover. Set to manual/pressure cook for 1 minute. Quick release after cook time. Stir and taste, adjusting seasoning as needed.
Divide taco mixture into zucchini boats, then top each with 2.5 Tbsp of shredded sharp cheddar cheese.
Bake for an additional 15-20 minutes, or until the filling gets bubbly, the cheese starts to brown and the zucchini is fork tender. I like to broil for the last minute or so to get the cheese topping extra crispy! Garnish with fresh pico, avocado, Greek yogurt, and cilantro.