Jim,
The sky's the limit with these kids. I'm not really familiar with vocational tech so you have to fill me in. Are they learning specific cooking skills like pastry or specific cuisines like French? Or, are you open to creating the curriculum. Are you working in a full kitchen where you can prepare anything? Also, how long is the course? Kids this age love to cook things they cannot pronounce and are relatively easy to make. Just keep a close eye on any chopping going on. I recently taught high school kids to make a dinner party menu including herbed pork roast with a mustard cream sauce, haricot vert amandine, a salad that I can't remember right now but showed them a couple of techniques for emulsifying the dressing, duchess potatoes, tarte tatin and an appetizer I can't remember off hand. Anyway, they loved it and did a great job. Hope this helps.
Dickie