Can I grow lettuce indoors?  

Yes, you can. It is one of the easiest things to grow and the fastest to harvest. A friend of mine grows lettuce in those disposable drinking cups you see used at parties. You just have one plant per cup and harvest as you need. 

You will need a grow light. Lettuce doesn't need to be pollinated but you will need plenty of light and healthy soil. You can get some grow lights fairly cheap on Amazon. I used on for my clementine tree since we get cold winters here.

I have done it before. I used a sunny window. It worked fine but I think using a grow light would be better as my plants were small and stayed small. There are grow light kits you can get these days as well.

Do you like spinach? I find that easier to grow indoors. Either way, both can be grown inside. You just need to make sure the plants get enough water, light, and the soil has some plant food in it.

You can grow anything you want indoors, including pot !!!