I am in a similar position to the original poster, and considering a change of career to move from the computer to the kitchen. I was looking for a short course by way of introduction, and considered Leith's and Cordon Bleu. After more looking around, I found a course that suited me better (less time commitment): a one-month cookery diploma at Ashburton Cookery School. There were a wide range of people on the course: a couple of prospective career-changers like myself; some already working as chefs (one on a luxury yacht); some wanting to set up their own business in catering; and one person there just for fun. The teaching was excellent, focussing on good quality local ingredients, and working every day towards a tasting menu in the evening. A vast amount was covered in the four weeks. The main drawback for someone considering a career as a chef was that it was in a teaching environment, not a real kitchen. The two days' work experience were great (and one of the main reasons I opted for this course). I spent two days with a friendly team in a hotel on the edge of Dartmoor. Two people who completed the course are now working in professional kitchens. I am proceeding more cautiously, and would like to gain some more real-world experience before making the leap from my comfortable 9-5 job, but I'm hoping to get a work placement in the autumn.