wholehearted; heartfelt; sincere
Describes an action, gift, or message that is done with genuine care and feeling. Often used in the past tense as a modifier.
I was moved by her heartfelt letter.
This dish is made with so much care and is very delicious.
Phrase composed of 心 (heart, mind) + が (subject marker) + 込められた (past passive form of 込める 'to put into'). Literally 'heart has been put into'.