The Discarded Fiancée and the Cold-Hearted Marquis

Melfy has been abused by her family since she was a child and forced to cook as the "cook's daughter." One day, her fiancé, Shallow, suddenly breaks off their engagement. His new fiancée turns out to be Melfy's stepsister, Avaricia...! With nowhere to go, Melfy ends up working as a chef for the "ruthless marquis," Luke. Luke, known as the "magician of ice down to his heart," is transformed by Melfy's special cooking!

(Source: Kodansha, translated)