Adverb
in a stolid manner
Source: WordNetThere's no reason why women shouldn't behave like rational beings,” said Simon stolidly. Poirot said dryly: "Quite frequently they do. That is even more upsetting! Agatha Christie
he said `no' stolidly Source: Internet
From outside, Armand stared stolidly through the doorway, and into the walnut-colored, wooden piano at the center of the bar. Source: Internet
The Guatemalans stolidly held their ground in their first few inches of America. Source: Internet