Source: a booklet for Pessach from Bar Ilan school in Rio de Janeiro.
Soak the matzot for 3 minutes in warm water with salt. Put out the maximum water possible and pick them as much hole as possible. Oil a pie pan and fold with half the matzot. In a pan over the stove, brown the onion, add the meat salted, and with garlic, pepper, parsley and green onions, and brown it. Let cool. Add the mashed potato mixed with 1 beaten egg. Put this filling over the matza in the pan and cover with the other half of matzot. Pour over the remaining beaten egg and bake for 15 to 20 minutes till golden.