Parched grain was a food that did not require lots of preparation. It was an easy and quick meal. The fact that Israel is able to eat this food was a tangible sign that their wilderness exile was indeed over. They ate manna until such a time as they came into the promised land (Exodus 16:35). Now they would eat from the fruit of vineyards and olive trees that they did not plant (Deuteronomy 6:11).
11 And the day after the Passover, on that very day, they ate of the produce of the land, unleavened cakes and parched grain.