Line a 13 x 9-inch baking pan with pieces of aluminum foil (heavy duty foil is recommended) that are long enough to overlap over the pan with plenty of room underneath. Place the beef, vegetables, aromatics, and the potato in the pan and toss. In a bowl dissolve the bouillon cube with the water then stir in the flour until blended. Pour the mixture over the meat and vegetables and spread evenly in the pan. Sprinkle the mixture with salt, pepper, and thyme, and toss in the bay leaf. Bring the edges of the foil together and tightly seal all edges. Cut 2 or 3 slits in the top of the foil dome for steam to escape. If the child wants to put the stew in the oven, don’t preheat it. Slide the pan in the oven and then turn it to 375 degrees and cook for about 2 hours 15 minutes, or until the potatoes and vegetables are tender. Remove from the oven and CAREFULLY cut the foil away, stir, and serve. (Serve over cooked rice for a south Louisiana-style stew.) If you preheat the oven, cook this one dish meal for about 2 hours.
If you are cooking a commercial meal in a bag with your children, read and follow all instructions. In all cases, supervise your children closely in the kitchen.