Cover and cook until the onion is soft, about 20 minutes.
Cover and smoke until the tomatoes are soft, about 25 minutes.
Lower the heat and cook very slowly until they are soft, about one hour.
Lower the heat and cook until onion is soft, about 5 minutes.
Reduce heat and simmer until soft, about 15 to 20 minutes.
There was nothing soft about her dedication to his memory.
There was nothing soft about him when he did it.
There was nothing soft about this man, except perhaps his heart.
Cook until the vegetables are very soft, about 15 minutes.
Cook until the potatoes are nearly soft through, about 15 minutes.