Here's one of my quick standbys. I originally got this from cooking light and I love the way it sits on the taste buds.
2 1/2 cups vidalia or other sweet onion - thinly sliced
1 can chipotle chiles in adobo sauce
1 lb ground sirloin
1/2 cup chopped green bell pepper
2 tablespoons tomato paste
1 teaspoon kosher salt
1/2 teaspoon ground cumin
8 oz can no salt added tomato sauce
Heat a small nonstick saucepan over medium heat. Coat with cooking spray. Add the onion and cover. Cook for 8 minutes stirring frequently until golden brown. Remove from heat.
Remove one adobo chili from the can and chop finely. Set it aside with approx 1 teaspoon of sauce. I normally bag up the rest of the chilies in individual mini bags with a little sauce and freeze them.
In a large nonstick pan coated with a little spray cook the ground sirloin until brown. Add the green bell pepper and cook for 2 minutes. Then add the chipotle chili, adobo sauce, tomato paste, salt, cumin and tomato sauce. Cook for 3-5 minutes, stirring occasionally.
Spoon 1/2 cup of beef over the bottom of half a bun, and then top evenly with some onions and the rest of the bun. Some people like grated cheddar added on top too.
It's quick, it's yummy and spicy and it's relatively low fat, what's not to love!!!!!