Fresh from the garden yellow summer squash is naturally sweet. If you are using grocery store squash you might consider stirring in about a teaspoon of sugar.
3 Tbsp butter
1/2 medium onion, chopped
1/2 tsp salt
1/2 tsp black pepper
2 pounds yellow squash, sliced
1. In a large saucepan, melt the butter and saute the onion until softened. Season with the salt and pepper.
2. Stir the squash into the pan as you slice it.
3. Continue cooking, stirring often, until the squash is cooked down a bit, as tender as you like.