Glossary of terms

Oat flakes are flat pieces of oat grain produced by steaming and rolling. They are among the healthiest breakfast foods thanks to their high content of fiber, protein, and beta-glucans, which help lower cholesterol levels. Oat flakes are prepared as porridge with milk or water, and used in muesli, granola, smoothies, baked goods, and cookies. They come in fine, medium, and coarse varieties. Oat flakes have a low glycemic index and provide long-lasting energy. They are the base for popular overnight oats.

Offal spread is a traditional Czech meat product made from organ meats, mainly liver, heart, and lungs, combined with barley groats or bread rolls, spices, and onion. The mixture is baked in the oven or boiled and served as a spread on bread or as a side dish. It has a rich, distinctive meaty flavor with notes of marjoram and pepper. It is a typical dish of traditional pig slaughter feasts and winter cuisine. The spread is prepared in various regional variants, with each family having its own recipe. It is rich in iron and B vitamins.

Okonomiyaki is a Japanese savoury pancake made with cabbage, batter, and various toppings. The name means grill what you like. A classic street food from Osaka and Hiroshima.

Okroshka is a refreshing Russian cold soup made with bread kvass, diced cucumbers, eggs, radishes, and fresh herbs.

Olive oil is a plant oil obtained by pressing the fruit of the European olive tree. It is the cornerstone of Mediterranean cuisine and one of the healthiest fats due to its high content of monounsaturated fatty acids, particularly oleic acid. Extra virgin olive oil is obtained from the first cold pressing and has the finest flavor and highest quality. Olive oil is used for salad dressings, marinades, baking, and frying over moderate heat. It is also a popular ingredient in cosmetics. The main producers are Spain, Italy, and Greece.

Olives are the fruit of the European olive tree, which has been cultivated in the Mediterranean for thousands of years. Fresh olives are bitter and inedible, so they must be cured in brine, vinegar, or lye before consumption. Green olives are harvested unripe, while black olives have ripened on the tree. Olives are enjoyed as a snack, added to salads, used on pizza, in pasta dishes, and in Mediterranean cuisine.

Olivier Salad is a Russian potato salad made from potatoes, carrots, eggs, peas, and meat mixed with mayonnaise, essential on the New Year's Eve table.

Olluco con Charqui is a traditional Andean dish of olluco tuber braised with dried llama or alpaca meat, seasoned with Peruvian spices.

The onion is one of the most widespread vegetables in the world. Cultivated for thousands of years, it forms the foundation of dishes across all cuisines. It comes in many varieties from white through yellow to red. The onion is indispensable in preparing sauces, soups, stews, and salads. It contains sulfur compounds giving it its pungent aroma and tear-inducing effect.

Oregano is an aromatic herb from the mint family, native to the Mediterranean region. It has a strong peppery and slightly bitter flavor with warm undertones. It is an essential ingredient in Italian and Greek cuisine, used in pizza sauces, pasta dishes, salads, and grilled foods. Oregano is available fresh or dried, with the dried form having a more concentrated aroma. It contains antioxidants, vitamin K, and iron. The herb also has antibacterial properties and is used in traditional medicine.

Ossobuco is a traditional Italian dish from Milan, made from cross-cut veal shanks with marrow bone in the center. The meat is first seared, then slowly braised in a tomato sauce with vegetables and white wine. The hallmark of the dish is the bone marrow, which adds a rich, deep flavor. Ossobuco is traditionally served with risotto alla milanese flavored with saffron. It is finished with gremolata, a garnish of lemon zest, garlic, and parsley.

Oštiepok is a traditional Slovak semi-hard smoked cheese made from sheep's milk or a blend of sheep's and cow's milk. It has a distinctive spindle shape with decorative patterns on its surface, created by pressing in carved wooden molds. The cheese has a golden to brown rind from smoking and a mildly salty, lightly smoked flavor. Oštiepok holds a European Protected Geographical Indication and is produced exclusively in Slovakia. It is served as a snack, grilled, or added to salads.