Slice each zucchini in half lengthwise. Scoop out the center in order to create a well. Roughly chop and save all of the zucchini that you scoop out for later.
Spray or brush zucchini boats with olive oil. Sprinkle them with about a half teaspoon of the garlic herb seasoning. Heat a grill over medium high heat and set the oiled zucchini boats cut side down. grill for about 5 minutes without turning in order to seal. Alternatively, you can bake in a 450 degree oven, cut side down, for 5-10 minutes. Set aside.
In a large skillet over medium high heat, melt 2 tablespoons of butter.
Add shrimp to hot melted butter. Add remaining garlic herb seasonings as well as 1 tablespoon lemon juice. Allow to cook until bottom side starts to turn golden brown, about 5 minutes, turn and cook for another minute. Transfer to a bowl and set aside.
In same pan melt remaining 2 tablespoons of butter. Add remaining zucchini and artichoke hearts. Cook until soft, about 5 minutes. Add garlic and saute for another 1-2 minutes.
Place grilled zucchini boats on a baking sheet. Fill with cooked zucchini filling. Tear each shrimp into smaller pieces and place on top of zucchini filling. Top with grated parmesan cheese.
Heat under broiler until cheese turns golden brown, about 5 minutes. Serve warm.