In a large skillet, heat the olive oil on medium. Add in the chicken, season with salt & pepper to taste, & saute for 5 minutes. Stir in the diced onions & cook until the chicken is cooked through. Stir in the spices, jalapeno, black beans, corn, & baby spinach and cook until the spinach has wilted. Remove from the heat, and stir in the pepper jack cheese.
Spoon about ¼ cup of filling into the center of each taco sized flour tortilla, and roll up like a burrito. Brush each side with a good coating of olive oil, and place in a baking dish. Bake for 20-25 minutes, flipping halfway through, until crispy.