Step 1 Rinse the limas under running water, then place them in a 5-quart saucepot. Add the water, garlic, onion and 1 teaspoon of salt. Bring to a boil. Reduce the heat to a simmer and cook, partially covered, just until tender but not mushy, 40 to 50 minutes. Drain the beans, reserving 1/4 cup of the cooking water for the dressing. Remove the onion. Place the beans in a large bowl and set aside.