Take some Maror (the minimum amount is 1 Kezayit, which literally means "the volume of an olive"), dip it into the Charoset, shake off the excess Charoset, and eat it.

Say the following blessing:

.בָּרוּךְ אַתָּה ה', אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם, אֲשֶׁר קִדְּשָנוּ בְּמִצְוֹתָיו וְצִוָּנוּ עַל אֲכִילַת מָרוֹר

Baruch atah Adonai, eloheinu melech ha'olam, asher kidishanu bemitzvotav vetzivanu al achilat maror.
Blessed are You, Lord our God, King of the Universe, who has blessed us with God's commandments and has commanded us on the eating of maror.


haggadah Section: Maror