Normally you translate 'Laver mad' with cooking, so I think this sentence could also be translated to 'The bear has cooked'.
"The bear is cooking" = "Bjørnen laver mad" (The bear is currently standing over the pots and cooking)
"The bear has cooked" = "Bjørnen har lavet mad" (The bear is NOT currently standing over the pots and cooking)
There is really no verb in Danish for "cooking"? You need to "make food" all the time?
"koge" http://ordnet.dk/ddo/ordbog?query=koge is casual and old-fashioned term for making food. It is a present term for heating water to boiling temperature.
"At lave mad" can also be used for uncooked food, thus prepared is a better general translation.