I don't like people dropping into my kitchen and start stirring my salans or especially washing dishes...I prefer to work alone. Cutting up salad is fine though.
I always wonder how to tell someone that I REALLY don't want their help? :(
Simple solution would be "aap mehmaan hain aap baitheye aur enjoy kariye." I remember once this lady forcefully tried to help me in my kitchen & I kept on telling her to just enjoy herself & I am fine. She took offense to it & was like "Bint be fikar raho mai tumharay kitchen may kuch mess up nahi karongi. Mai khaali help karwa rahi hon. I told her straight up but in a nice way kay I'll be more comfortable alone & everything is already done anyways.
Even my mom comes over she always wants to help & all & then I can't concentrate. If its her or some other ladies close to me I just ask them to take a chair & sit by the kitchen while I work. That still slows me down though.
I don't like it when the guests try to help me with cooking, i get nervous and mess up big time. Although, i don't mind when they help me with other stuff like doing dishes, sweeping floors etc. It's just the cooking part where I don't want anyone around me.