Preheat oven to 350F. Boil & cook pasta shells according to package instructions. Let drain & cool. Set aside.
For the beans: In a large pot, heat oil and then add in oregano, parsley, red pepper flakes, garlic powder and red chili powder. Once spices start to sizzle, add in 2 cans of beans and begin to mix. Add in taco seasoning, 1 tbsp water and mix until well combined. Next add in siracha sauce, taco sauce, sour cream and salt/pepper according to taste. Continue to stir and mix well. Let the beans heat for 10 minutes, stirring constantly. Set aside. The beans will start to thicken up as they cool.
Combine the veggies with the beans and mix well. Add in 1/2 cup of cheese into this mixture, and mix until combined. This will be your stuffing for the shells! You can sprinkle additional spices on top of this mixture, if you desire! I do!
Coat a 5 qt & a 3 qt baking dish with nonstick cooking spray. Spread enchilada sauce on bottom of both baking dishes. Spoon bean, veggie and cheese mixture into each shell. Then sprinkle with cheese. Place stuffed shell open side up in the dish. Repeat and place until all shells are filled. Once both dishes are filled, pour the remaining enchilada sauce on the shells and bake for 25 minutes. After 25 minutes, take out the pan and top shells with remaining cheese and then bake for another 7-10 minutes or until the cheese melts.
Top with green onions & sour cream!