Lentil Sloppy Joes

Name: Lentil Sloppy Joes
Ingredients: 1 cup Uncooked Lentils (brown Or Green); 4 cups Boston Lager, Or Dark Ale Beer (Water Or Vegetable Broth Are Great Substitutes); 1 Medium Yellow Onion, Diced Small; 1 Green (or Red) Pepper, Diced Small; 1 Tablespoon Olive Oil; 2 cloves Garlic, Minced; 2 Tablespoons Chili Powder, Or To Taste; 1 teaspoon Black Pepper, Or To Taste; ½ teaspoons Kosher Salt; 12 ounces, fluid Tomato Sauce; ¼ cups Tomato Paste; 3-½ Tablespoons Maple Syrup; 1 Tablespoon Yellow Mustard; 4 Udi Whole Grain Hamburger Buns (if You're Gluten-free) Or Any Sandwich Bun; Your Favorite Sandwich Toppings