I have come to the conclusion that I, as a vegetarian, wouldn't survive as a noblewoman in the Medieval time period.
The upper class diet consisted of mainly meat (beef, venison, mutton, pork, poultry, and other game), fish, shell fish, fruit, spices, cheese, and limited number of vegetables (those grown above ground - see http://www.middle-ages.org.uk/middle-ages-food-and-diet.htm). Their main bread was white flour bread called manchet bread (recipe here).
The lower class diet is more to my personal taste. Pottage (a vegetable stew usually containing peas or lentils and other vegetables from the garden - recipe here), dairy products, non-game meats (like beef, pork and lamb), fish (limited by location), homegrown vegetables, homegrown fruit, and herbs. A barley or rye bread would round out the daily meals.
The Medieval Cookery looks like a great resource of recipes. I am looking forward to exploring their archives.
Which diet would suit your culinary tastes?