2 tablespoons vegetable oil
1/2 small onion, finely chopped
1 small carrot, finely chopped
1/2 bell pepper (red or green), finely chopped
1/2 cup ketchup
1 clove garlic, finely chopped
1/2 cup dried brown lentils, picked over and rinsed
1/4 teaspoon dried oregano
Kosher salt and freshly ground pepper
Kosher salt and freshly ground pepper
8 ounces ground beef
1 tablespoon Worcestershire sauce
6 whole-wheat hamburger buns, toasted
6 slices cheddar cheese
Sliced pickles and/or pickled jalapeno peppers, for topping (optional)