Boiled yellow squash is great for adding to casseroles and also makes a nutritious side dish on its own. Choose a squash that's heavy for its size, firm and bright yellow with few or no blemishes or bruises and no moist patches. Smaller squash—no bigger than a half-dollar in diameter—are more tender and less bitter than ones that have been allowed to grow large.
Preparing the Squash
Wash and dry the squash. Leave the skin on. For each piece, remove the end from the neck and discard; typically, the other end is removed, too. Cooks often discard the neck, but it has the same nutrition and taste as the body of the squash, so you can keep it if you want. Cut away any bruises or blemishes. You can leave the rest of the squash whole or cut it into wheels or cubes of any size; just keep all pieces approximately the same size for even cooking.
Flavoring the Squash
For flavor, you can add salt, a pinch of sugar, butter, herbs, spices or a chicken bouillon cube to the water prior to boiling. You can also boil squash in vegetable or chicken broth instead of water. White or yellow onion imparts even more flavor; add 1 part onion to 8 parts squash.
Squash destined for a casserole only needs a dash of salt in the water prior to boiling.
Boiling the Squash
To cook squash pieces, fill a pot with just enough water to cover the squash, and bring to a boil over medium-high heat. Once the water is boiling, lower the heat to medium and add the squash pieces. Leave uncovered. Small pieces of squash should cook in about 4 minutes.
To boil whole squash, fill pot with enough water to cover the squash by at least 1 inch, and bring to a boil. Lower the heat to medium-low, add the whole squash and cook with the lid on for at least 30 minutes.
Check frequently and remove the pot from the heat as soon as the squash reaches the desired softness.
Strain out the water or remove the squash with a slotted spoon. Serve, or add it to a casserole recipe.