The Inn at the Crossroads blog has medieval recipes for Oxtail Soup, Leek Soup, Beef and bacon pie, Pork pie, Fruit tarts, Apple crisps, Hildegard of Bingen's spiced cookies, Spiced plum mousse, Boiled beans, Almond milk, and Mulled Wine, amongst others.

This page on the website of the British Museum also includes recipes to recreate Medieval Creamed fish, Roasted steak, Mushroom pasties, Lamb stew, Haddock in sauce, Cherry pottage, Cream custard tarts, Rose pudding, and Mulled wine.

There are plenty of surviving medieval cookbooks (translations of many of which can be found here), but they're very difficult to use alone. because they tend to be maddeningly vague about measurements. This, for example, is a translation of a 13th century French recipe for pancakes:

>Here is another dish, which is called white pancakes. Take best white flour and egg white and make batter, not too thick, and put in some wine; then take a bowl and make a hole in it; and then take butter, or oil, or grease; then put your four fingers in the batter to stir it; take the batter and put it in the bowl and pour it through the hole into the (hot) grease; make one pancake and then another, putting your finger in the opening of the bowl; then sprinkle the pancakes with sugar, and serve with the "oranges."