catflap.org Online Dictionary Query

  let sb. join in with the cooking /lˈɛt ˌɛsbˈiː dʒˈɔɪn ɪn wɪððə kˈʊkɪŋ/
  jdn. mitkochen lassen
   see: take part in sth., to (actively) participate in sth., join in sth., taking part, participating, joining, taken part, participated, joined, takes part, participates, joins, took part, participated, joined, take part in the combat, join in the conversation, join in speaking sth., join in the game, Parents need to engage with sport and encourage their children to participate/join in.