Preheat the oven to 350℉. Spray a rimmed baking sheet or pan with nonstick spray.
Fill a medium saucepan ¾ full with water. Add the chicken stock/broth. Bring to a boil over medium high heat. Add the pasta and cook, stirring once in a while, for 8 to 10 minutes, or until the pasta is tender. Drain and rinse the pasta. Set it aside and clean out the pan.
While the pasta is cooking, use a small spoon to scrape out the insides of each tomato or zucchini half. Don't scrape the vegetable all the way to the skin- just enough to make a deep pocket where you'll be able to put the macaroni stuffing. Place the vegetables skin side down in the prepared baking sheet.
Warm the milk in the saucepan over medium heat. Whisk in the mustard, then whisk in the flour, pepper, basil and oregano. Cook and stir for 1 minute, until thickened. Add 1 cup of the cheese and whisk until smooth. Stir in the cooked pasta.
Divide the pasta between the hollowed out vegetables, mounding as needed. Top off the mac with the remaining ½ cup of cheese. Sprinkle with panko crumbs. Bake, uncovered, for 30 minutes.
Notes
Try using Swiss or Havarti in place of cheddar.
Try stuffing other vegetables such as bell peppers, small eggplant or portobello mushrooms.