Wash all the veggies first. Cut up all the veggies into small portions. Sprinkle salt on them all and let it sit in the fridge until the croissant is fully cooked.
Roll the dough on a cookie sheet or into a 9x11 baking dish cover the entire bottom of either dish in a rectangle shape. Stick it into the oven and let it cook until golden brown. Once its done cooking let it sit out for 10 min to cool off. You can take it out of the baking dish onto a flat surface.
Once cool, take the cream cheese and chives and spread it all over the laid out croissant sheet. Take the veggies out of the fridge and sprinkle that evenly over the cream cheese. Then sprinkle the shredded cheese over the veggies. Cut into 12 squares and serve or cover and chill in the fridge until later.