Bean-Mushroom Sloppy Joes

In a large skillet, heat olive oil over medium heat. Add mushrooms, onion and green pepper; cook 5 to 7 minutes or until tender, stirring occasionally.

Push vegetables to one side of skillet. Add half of the navy beans; mash with potato masher or fork. Stir in remaining beans, tomato sauce, brown sugar, Worcestershire sauce, mustard, chili powder and salt. Simmer, uncovered, over medium-low heat for 10 to 12 minutes, stirring occasionally, until thickened enough to mound. Stir in sunflower kernels. Spoon onto toasted buns lined with spinach leaves.