Grilled mexican stuffed green bell peppers

5 green or red bell peppers 6 chicken tenderloins 1 cup cooked red or black kidney beans 2 teaspoons chili powder 1 teaspoon garlic powder 1/2 teaspoon cumin powder 1/2 teaspoon salt 1 table spoon vegetable oil Bechamel sauce: 2 table spoons flour, 1 table spoon unsalted butter, 1 cup milk, 1/2 cup shredded Cheddar or mozzarella cheese

1. Prepare the peppers: wash, cut off the end caps from peppers, scrape off all the seeds and white core from inside. 2. Boil chicken in a pot until tender and cut into cubes. Set aside. 3. Peel onion and cut into small cubes. Heat a table spoon vegetable oil over medium high heat. Cook onions until lightly browned, add chicken pieces, cooked beans, salt and spices. Mix thoroughly and cook for 5 minutes with lid closed. 4. Stuff peppers with filling mixture up to the top. Grill in the oven for 25 minutes until lightly charred. 5. Meanwhile, prepare the sauce: whisk together flour with milk and heat in a small pan, bring to simmer and cook for 2 minutes until it thickens. Add cheese and whisk vigorously. Spoon sauce mixture over bell peppers and grill in the oven for 5-7 more minutes until the tops are golden brown.