Divide salt evenly among 2 (9 by 13-inch) metal pans divide salt evenly. Heat your oven to 400 degrees F and put the pans of salt into the oven to heat. When the oven reaches 400 degrees F, allow the salt to continue heating for another 15 minutes. After 15 minutes have passed, put the shrimp on top of the salt in 1 of the pans. Then cover with all of the salt in the second pan. The shrimp should be evenly and completely covered. Roast for 8 minutes. Remove from oven and check 1 shrimp for doneness. The shrimp should be opaque and white and pink in color. If not done, return to oven for 1 to 2 minutes. Serve immediately.