Wash 1 1/2 pounds of green beans and dry them with a paper towel. Snap them or cut them into 1-inch long pieces, removing any blemishes. Place the beans in a pressure cooker. Add 1 to 1 1/2 teaspoons salt, 1 tablespoon cooking oil, and 1/2 cup water. Place the lid on the pressure cooker, turning to close tightly. Make sure the gasket in the lid is in place. Place the pressure release valve on top of the pressure cooker. Move the pressure cooker to a burner on the stove, and set it on medium high heat until the pressure release valve "jiggles" consistently. Turn the heat to low, being sure the value continues at a low "jiggle." Cook for 20 minutes. Turn off heat, and carefully remove the pressure cooker from the stove and place it in your sink. Carefully and cautiously remove the pressure release valve to let the steam escape. This will take a minute or so. Don't rush it. Do not put your hand near the steam as it escapes. *Do not open the lid until all of the steam has escaped, and the pressure is equalized*! Now, open the lid, and remove the Country-Style Green Beans to a nice serving bowl. Serve immediately! These may be reheated, and usually taste better the second time around. These Country-Style Green Beans are a staple of Kentucky cooking, and also much of the South!