Preheat oven to 400. Cut squash in half lengthwise. Sprinkle with salt and pepper, and roast, facedown on parchment covered cookie sheet, for 30 minutes or until you can easily poke with a fork. Peel and cut into cubes when finished cooking.
While squash is cooking, in a large pot sauté onion in a small amount of water until soft, adding more water as onion sticks. Add garlic and cook one more minute.
To the pot add beans, tomatoes, corn, jalapeno, cubed squash, and enough water to reach desired thickness. Cook until warmed through and squash is fully cooked.
Stir in basil, and season with desired amount of salt and pepper.