I used to buy pots of it in the supermarket. This is a genuine Swiss basic recipe but as you can see you can have different variations.
"Here is the original recipe, from 1928 for this world famous dish!
1 portion
1tblsp. rolled oats
3tblsp. water
The oats are soaked for 12 hours in the water
1tblsp. lemon juice
1tblsp. ccondensed milk
2-3 apples
1tbls. ground hazelnuts
Mix the milk and the lemon juice with the soaked oats and grate the apples, with skin and core. into the mixture. Stir frequently, so that the apples won?t oxidise and turn brown.
The nuts are then scattered over the Muesli on the table to increase the content of protein and fat.
Nowadays you can mix and match to your heart?s content, swap condensed milk for yoghurt of any flavour, add fresh fruits and berries, raisins, nuts, ground or crushed, even chocolate chips, rolled oats and other flakes and bran can be added too! Some squirt whipped cream on top; others scatter pumpkin seeds over it, the next one uses roasted coconut??? etc. etc. As for sweetening you can add sugar, honey, maple syrup, Birnel etc
One thing to consider is do NOT add raw kiwi and pineapple to yoghurt based Muesli, both contain an enzyme that can make the milk products turn sour or become flaky. Of course these variations are nowhere close to the original recipe above, but nonetheless they are still very yummy and if you don?t overdo it on sugar and such it is still a healthy dish."
Otherwise Yeo Valley do a large pot of yoghurt
with seeds and grain to which you could add soaked oats and make something similar.
hth