Are you wondering what to do with the sauce left over from a previous meal? Is the bread threatening to turn stale in the bread bin or are the bananas turning brown in the fruit bowl? The tips of Mika Pesonen, top chef and the captain of Fazer's Culinary Team, will help you to save food that threatens to turn into waste and whip up something delicious instead.

Dry rolls, bruised apples, wilted kale. The average Finn throws approximately 24 kilos of food away every year. The majority of food waste is composed of quickly perishable fresh produce, such as fruit and vegetables or leftovers from home-made meals.

The national food waste week organised by the consumer alliance Kuluttajaliitto will be held on 29 August–4 September 2016. Its goal is to increase the appreciation of food and reduce food waste. This is the fourth time that the week is being held, and Fazer is also involved.

“A job well planned is half done” is the motto of Mika Pesonen, the captain of Fazer's Culinary Team. In many home kitchens, a few small steps would go a long way towards reducing the amount of food waste. These tips given by Pesonen will help you to reduce food waste at home.

1. Roast root vegetables and purée fruits that have gone soft

According to a study by the Ministry of Agriculture and Forestry, the articles that most often spoil in Finnish households consist of vegetables and root vegetables – some 22 million kilos a year in total. Bananas, apples and other fruits are also often easily left at the bottom of a fruit bowl to go brown and soft.

Root vegetables that are past their prime turn delicious when you roast them in the oven. Roasted root vegetables are good in a salad, for example, which turns into a filling meal when you throw in some fresh cheese.

Of the products featured in the produce section, fresh herbs are another article that easily ends up as waste. Once you have used what you need for a meal from a pot or bunch of herbs, chop up the rest immediately and freeze it in a small container. Basil, parsley and other aromatic herbs also lend themselves easily to being made into herb oil, which keeps in the fridge a lot longer than fresh herbs.

Fruit that have gone soft are perfect for quick smoothies, in which you can incorporate even the blackest bananas inconspicuously. Somewhat overripe bananas are also ideal for a batch of trendy banana pancakes. Mash the bananas and mix in an equivalent amount of eggs. Fry the pancakes in oil or butter and serve with fresh or frozen berries, for instance. By the way – did you know that you can also freeze bananas? Once thawed, you can purée the banana and use it in the dough of a banana cake.

2. Be creative with leftovers

“Frying makes everything taste good!” is one way of putting it. The further processing of fresh produce and leftovers is not only key to reducing food waste, but to new and tasty food experiences.

Puréed soups and leftover porridge make for tasty ingredients in baking. Use what's left over from a puréed soup to make delectable bread and bake porridge into rolls or a pancake.

The leftovers of a sauce can be handily converted into another meal when you add some more vegetables to it. A tomato sauce, on the other hand, provides a terrifically tasty base for a variety of dishes. Freeze a tomato soup or the tomato sauce left over from a pizza to wait for the next spaghetti Bolognese day.

3. Use your senses to assess dairy products

Dairy products do not usually come with a use-by date, but a best-before date. If the dairy product has been stored in the correct way at a sufficiently low temperature, in an airtight container and in such a manner that it has not been contaminated with breadcrumbs or other food, it will remain usable for several days beyond its best-before date. This is why you should rely on your senses, in addition to the date printed on the package, to assess whether the product is still usable. Your nose will prove the best judge, as it is very easy to tell when milk has gone sour.

Milk and cream that are past their best-before date are suitable for food that is cooked, such as sauces and pastries. Pour the last drops of cream into a puréed soup or a sauce, and use the milk that is going to waste as a base for a pancake batter, the ingredients for which can often be found in every household.

In a dough or batter, sour can also transform into sweet. Cultured dairy products, such as yoghurt and curdled cream, are great ingredients for various kinds of sweet pies, for example. Buttermilk can be turned into sweet buttermilk buns in no time at all.

Cheese usually only improves with age. Grate leftover bits of cheese into a pizza, for example, which is, in any case, good for almost any other ingredient you can find in your kitchen cupboards. Cheese can also be used in a cheese sauce for, say, lasagne.

4. Save dry bread by toasting it

Bread packaged in a paper bag usually tastes fresh only for a few days, and stale bread often ends up being discarded. When toasted or fried on a pan with a little olive oil and garlic, however, even bread that has gone a little stale tastes great. A bone-dry hunk of bread can still be toasted into croutons to be used in soups and salads or ground into breadcrumbs to be used in baking.

Bread packaged in plastic bags, on the other hand, will not dry, but may become mouldy. This is why it is not a bad idea to store toast, for example, in a cool and dry place. Particularly in small households of one or two people the final slices in a bag of toast often end up getting mouldy. The economical way, therefore, is to put the bread in the freezer when it is fresh and to take out a suitable number of slices whenever necessary.