Put the mixture in the casserole, heat the oven and cook it.

Occasionally stir it up to avoid that the jam abke on the bottom . The scum which sortiers at the surface must be removed.

If the fruits are not mature enough, you need to crush them a little.

How long should you cook the fruits depends on their maturity.
Because we not used jellied sugar (it does not exist at the time of our grandmothers) and because we have a mixture of fruits very mature and less mature, the cooking takes about 1.5 hours.

The jam is good if it is very viscous. You can test this by giving a bit of jam on a plate and see if it is thick.