This might take 15 minutes to prepare if you're a professional chef, but not to us average cooks. In saying that, it was definitely worth the wait. It was so good. Next time though I would not parboil the vegetables because they were completely cooked after I parboiled them, and so this dish was quite mushy and I would make extra sauce just to cover the whole dish. A note to the people who did not like the flour, if it tastes of flour then you didn't cook the flour and butter long enough and also the flour is essential in thickening the sauce, you could use cornstarch instead. Hope this helps.