Having a high focus seems to give more points towards the next level when you practice or use a skill. Reading gives you skill faster while your focus is high and gives skill less often while your focus is low, forcing you to read for longer.
Usually though, many recipies, especially at higher levels, require anywhere from 15 minutes to 2 hours or more if your talking about mechanics or construction and by the time you finish, both your good mood, and your focus have worn off. At least, food related bonuses wear off quickly, even if you stack them twice.
However, gourmand is good for other reasons, as it allows you to boost your mood higher with just food incase you really need to craft or something while your mood is terrible.
But the focus boost in the begging is invaluable if you need to train certain skills to moderate levels quickly. Things like dodge and cutting weapons for instance.