Could it be: Myslím na tvoji polévku.
Added, thanks. Next time just report it with the button.
And what happened with that soup?
Would there be a grammatical difference in Czech between 'I think about your soup' which seems infinitive, and 'I am thinking about your soup' which is the present tense?
"I think" is the simple present (not the infinitive).
"I am thinking" is the present progressive.
For the most part, a Czech verb can be translated using either, but pay attention to context!
Is there a difference between ‘I think’ and “I am thinking”?
Are you asking a question about English or about Czech? For the most part, Czech verbs can be translated using either the English simple present or the progressive (-ing) forms.
is tvou or tvoji more common?
Both are common.