Both my leaf lettuce and my arugula plants recently bolted in the heat wave we had here.

The arugula has not really been growing much in the way of leaves since then, instead it's growing a giant flowering stalk which is getting taller and taller every day. Is there anything I can still do with a bolted arugula plant or should I just yank it out?

As for the lettuce, I completely cut of all the leaves when I saw they had bolted, and assumed it was the end. But now a lot little lettuce leaves have begun to grow on the base. Are these leaves just as edible as the harvests I got before the plant bolted, or will they be bitter or off-flavor somehow?

I noticed even before the plant bolted the leaves were growing very fast and getting very big, and the texture and flavor were not very good. Should leaf lettuce never be allowed to grow too big? Should I always be cutting the leaves when they are small? What is the best time to harvest it for best flavor and texture?

Thanks!