Black Bean Burger

Name: Black Bean Burger
Ingredients: 2 1/2 pounds cooked black beans; 2 cups fresh cilantro, chopped; 1 cup breadcrumbs; 1/3 cup mayonnaise; 1 tablespoon plus 1 teaspoon cumin; 1 tablespoon kosher salt; 2 teaspoons chipotle powder; 2 teaspoon dried oregano; 2 teaspoon freshly ground black pepper; 2 tablespoons grapeseed oil; 6 slices pineapple, 1/2 inch thick each; 6 tablespoons unsalted butter; 6 brioche burger buns, split; 6 leaves Bibb lettuce; 6 slices tomato; 6 slices red onion; Vegetable chips, for serving