Summer Squash Casserole

• 1 1/2 pounds yellow summer squash, sliced
• 1 small onion, chopped, 2 1/2 ounces
• 4 ounces sharp cheddar cheese, shredded
• 1 egg, beaten
• 2 tablespoons mayonnaise
• 1 teaspoon granular Splenda
• 1/2 teaspoon salt, or to taste

In a large pot, cook the squash in boiling salted water to cover just until tender, about 8-10 minutes. Drain well and press between paper towels to remove the excess moisture. Meanwhile, in a small skillet, sauté the onion in butter until tender. Remove from the heat and stir in all but the squash. Combine everything in a greased 1 1/2 quart baking dish. Bake at 350º 30-40 minutes or until set and the top is bubbly and starting to brown.