Tortellini Corn Chowder

1 tablespoon canola oil or butter
1 large onion, chopped (1 cup)
3 cups water
1 package (9 oz.) refrigerated cheese-filled tortellini
2 medium unpeeled potatoes cut into 1/2 inch cubes
1/2 pound fully cooked ham, cut into 1/2 inch pieces
1 can cream-style corn
1 can whole kernel corn
1 can evaporated milk
2 teapspoons chopped fresh or 1 teaspoon dried marjoram
1/4 teaspoon coarsely ground pepper

Heat oil in a stockpot over medium heat. Cook onion in oil, stirring occasionally until tender.

Stir in water, heat to boiling. Stir in tortellini, potatoes and ham. Heat to boiling, reduce heat. Cover and simmer 13 minutes, stirring occasionally until potatoes are tender.

Stir in remaining ingredients. Heat to boiling, reduce heat. Simmer uncovered five minutes.

(I got this out of one of my mom's diabetic cookbooks, so it must be healthy.)