Place the onion, potatoes, carrots, pepper, green beans, celery, creamed corn, broth, parsley, basil, and oregano in the base of a crock-pot. Cook on low for 6-7 hours or on high for 3-4 hours until potatoes are tender and cooked through. Season to taste with salt and pepper; depending on the saltiness of your broth you may or may not need salt. I usually add ½ teaspoon and go from there.
Whisk together the milk and cornstarch until dissolved. Slowly add the milk mixture to the chowder and cook on high another 30 minutes until thickened. Serve!