Zippy Shepherd's Pie

Ingredients

• 1 pound potatoes, peeled and chopped
• 1 tablespoon canola oil
• 1 pound ground beef
• 1 large onion, finely chopped
• 1 red bell pepper, finely chopped
• 2 cloves garlic, finely chopped
• 1 (14 ounce) can beef broth
• 2 tablespoons ketchup
• 1 tablespoon soy sauce
• 1 tablespoon worcestershire sauce
• 1 teaspoon mild curry powder
• 1 tablespoon cornstarch
• 2 tomatoes, coarsely chopped
• 1 (16 ounce) package frozen mixed peas and carrots
• 1/4 cup milk
• 1 tablespoon butter
• 1 cup shredded extra-sharp cheddar cheese
• salt and pepper to taste