Every outdoor plant can be an indoor plant with enough effort
Peppers can be grown indoors, and the leaves are also edible.
@scutiger What are the leaves like?
In my hydroponics setup I grow a variety of salad greens. I've been slowly adding plants trying to find the right amount to where I can have a fresh salad every day without throwing away a ton of excess. It's a neat conversation piece and I enjoy having the option.
Tomatoes can be grown pretty successfully indoors. Also prickly pear.
You can grow microgreens, and other green, leafy vegetables with the right conditions: full-spectrum light, deep enough soil, and keeping the soil moist. Lettuce and cabbage are very easy to grow.
I have a Lamb's tail, Anredera cordifolia, growing in a fairly low-light spot in my living room. Much of the plant is edible, the flavour is reminiscent of spinach.
