1. Preheat the oven to 400 degrees F. Cut the zucchini in half lengthwise and use a small spoon to scoop out the seeds, forming a shallow cavity. Finely grated one of the seeded zucchini into a bowl, salt and set aside. Liberally sprinkle the other zucchini shells with salt and place cut-side down on paper towels while preparing the filling.
2. Melt 3 tablespoons butter in small skillet over medium-high heat. Add the onion and pepper and cook, stirring often, until softened, about 5 minutes. Add the garlic and cook 1 minute longer. Lightly squeeze the grated zucchini to remove the excess moisture and add to the onions and peppers. Cook until the mixture dries slightly. Remove from the heat, stir in the panko, cheese, and thyme. Season with salt and pepper. Cool slightly.
3. Wipe the salt from the zucchini and dry as thoroughly as possible with paper towels. Divide the filling among the zucchini halves, mounding them slightly down the center. Place on a lightly oiled baking sheet and bake until the zucchini softened and the tops brown, about 20 minutes. Carefully transfer zucchini to a platter and serve warm or at room temperature.
Copyright 2010 Television Food Network, G.P. All rights reserved