Thanks to Anko, Pat Hammond and Scotso who provided invaluable tips on using agar agar as a substitute for gelatin in a tomato flan recipe. I followed the advice on the agar agar website and heated the tomato sauce in order to dissolve the agar agar. I ended up using only slightly less agar agar than gelatin, possibly because, as one poster noted, the acidity in the tomato sauce may impede gelling. Well, it turned out okay. The consistency of the flan wasn't as silky smooth as when I use gelatin but that's a minor quibble. There was also a slightly off taste to the flan, and I wonder if the agar agar wasn't responsible for that. (The recipe includes only tomato sauce, olive oil, garlic, fresh basil and salt and pepper.) Has anybody else noticed a funny taste from agar agar? And why oh why is it called agar agar instead of just plain agar?