Do you cover the pot while the beans and veggies are cooking? Or leave uncovered?

I would cook this the same way I cook a non-vegan version- which is uncovered. You want some of the liquid to evaporate in the cooking process to concentrate the flavors. The other reason is so help prevent the pot from coming to a rolling boil, which it tends to do if you cover the pot. You want the peas to retain shape, and if it goes beyond a simmer, they will tend to self destruct.