Q. Can you tell me the prayer which I am supposed to say whlie offering food to the Lord?

A. Make a plate with a little portion from each preparation.A Place it before a Picture of the Lord or the Deities and while ringing the bell in your left hand lovingly chant each of the following mantras three times:

nama om vishnu-padaya krishna-preshthaya bhu-tale
srimate bhaktivedanta-svamin iti namine
namas te sarasvate deve gaura-vani-pracarine
nirvisesha-sunyavadi-paschatya-desa-tarine

I offer my respectful obeisances unto His Divine Grace A.C. Bhaktivedanta Swami Prabhupada, who is very dear to Lord Krishna, having taken shelter at His lotus feet. Our respectful obeisances are unto you, O spiritual master, servant of Bhaktisiddhanta Saraswati Goswami. You are kindly preaching the message of Lord Chaitanyadeva and delivering the Western countries, which are filled with impersonalism and voidism.

namo maha-vadanyaya
krishna-prema-pradaya te
krishnaya krishna-chaitanya-
namne gaura-tvishe namah

O most munificent incarnation! You are Krishna Himself appearing as Sri Krishna Chaitanya Mahaprabhu. You have assumed the golden color of Srimati Radharani, and You are widely distributing pure love of Krishna. We offer our respectful obeisances unto You.

namo brahmanya-devaya
go-brahmana-hitaya ca
jagad-dhitaya krishnaya
govindaya namo namah

My Lord, You are the well-wisher of the cows and the brahmanas and You are the well-wisher of the entire human society and world.

You can also chant the Pancha Tattva and Hare Krsna mantras three times:

sri-krishna-chaitanya prabhu-nityananda
sri-advaita gadadhara srivasadi-gaura-bhakta-vrinda

I offer my obeisances to Sri Krishna Chaitanya, Prabhu Nityananda, Sri Advaita, Gadadhara, Srivasa and all others in the line of devotion.

Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare
Hare Rama, Hare Rama, Rama Rama, Hare Hare