Hello, I wrote an answer here about trying to gauge the affordability of medieval meat. As that answer says in more detail, the problem for the peasantry (at least post-Conquest in England) wasn't meat, but fresh meat. Animals were typically butchered for the winter on Martinmas, the 11th of November and without the luxury of hunting (at least openly), and barring the thinning out of old breeding stock in the spring, that meat then had to last several months. This meant that meat typically had to be preserved - whether dried, cured, smoked, pickled or salted - and rationed to last. Stews and pies were therefore a common means of ekeing out those meat supplies, as well as making preserved meat more palatable.

Two sources I return to often for these questions are Ælfric's Colloquy, a 10th Century Latin textbook in the format of a guide to a contemporary English community, and the 15th Century poem London Lickpenny, which paints a vivid picture of that city's many districts and markets written from the perspective of a poor Kentish farmer. We also have an array of contemporary art depicting markets and popular food and drink, whether in paintings, illustrations, or even murals. Ælfric suggests that fish was a popular and commonplace source of fresh meat for many people, and offered a great variety of choice from both maritime and riverine sources. Certainly, the fisherman who appears in the Colloquy suggests that, when he goes to market, he easily sells out his catch to the crowd there. Depending on your location, the fish available might include:

eels, pike, minnows and dace, trout, lamprey and any other species that swim in the rivers, like sprats... herring, salmon, dolphins, sturgeon, oysters, crabs, mussels, cockles, flatfish, plaice, lobsters and such like.

Mackerel feature again in London Lickpenny, when they are one of the plentiful street foods being sold by hawkers in the city's various markets. Other street foods include cooked pigs' feet and sheep's feet, hot peas (cooked in pods so presumably like a mangetout), rissoles, stews, and an assortment of pies. Contemporary illustrations show that bread rolls and small loaves were also sold by enterprising bakers to market crowds, although of course in a village setting, people would likely bake their own bread.

The 15th century Libro de componere herbe et fructi shows market traders selling onions and radishes, while the 13th century Les Cris de Paris (The Cries of Paris) details the various traders of the city's markets and their distinctive cries in a series of woodcuts. One of these includes a 'vegetable seller' who carries turnips and a variety of legumes: peas, lentils, chickpeas and the like. 14th and 15th Century depictions of market scenes (such as at Issogne) show cabbages, parsnips, carrots, peas, mushrooms, marrows, a wide variety of pumpkins and squash, garlic, radish, strawberries, blackberries, raspberries, gooseberries, hawthorns, rosehips, sloes, apples, crab apples, rowans, elderberries, cherries, plums and damsons.

Les Cris de Paris suggest that milk was a regular part of the diet, as there were apparently specialised milk hawkers at the Paris markets, who presumably collected surplus from dairy farmers and took it to market to sell, or indeed were themselves the dairy farmers selling their surplus. Cheese was therefore also a useful source of both protein and fat. An early 14th Century illustration from the Maastrict Book of Hours (British Library Stowe 17, Fol. 67r) depicts a woman carrying several small wheels of cheese in a basket on her way to a market, (In her other arm she carries a rabbit, illustrating that 'small game' hunting could still be a ready source of meat), and indeed one of the major markets in 14th Century Bruges was known as the Cheese Hall (Murray, 2011). Two 15th Century images (Campin's Nativity and the Armorial de Revel) both feature details illustrating peasant women carrying large baskets of eggs, which would suggest a certain commonality of consumption. Eggs certainly feature in a number of medieval recipes.

A fairly wide assortment of medieval recipes survive today in a number of manuscripts. While some are clearly limited to the wealthy (such as 'Cressy', a spiced, platted sweet bread containing a variety of dried fruits and saffron), others suggest that peasant food wasn't solely limited to stews. 13th Century sources (British Library 32085) include recipes for meatballs (known colloquially as oranges), pancakes, vegetarian ravioli stuffed with cheese and mushrooms, fruit pies and pastries topped with soft cheese, hawthorn soup, meatloaf and sausages. A 1340 text includes a number of blancmanges (which the 9th Century medical textbook known as Bald's Leechbook advises as good food for the ill and recovering injured), uses for almonds, hazelnuts, pine nuts and chestnuts, a 'rabbit stew popular in England and France' and fried eels, and 1380 source includes blood sausage, a hare broth, apple fritters, oxtongue, apple porridge, baked lamprey, lamprey soup and fish with a bread sauce/crust.

The 1390 Forme of Cury includes a bean and bacon broth noted as being 'a dish of the poorer householder', as was "caboches in potage" (a cabbage stew containing onions and leeks) and the similar "rapes in potage", a turnip stew. Also includes mushrooms fried with leeks, and a kind of pork and squash stew involving eggs.