Line a rimmed baking pan with parchment paper or foil and set aside.
In a medium bowl, lightly beat egg with fork. Stir in cornmeal, taco seasoning, salt, and pepper. Add beef and shredded cheese. Mix well (using your hands works best). Shape mixture into twelve meatballs (I like to use a 2" scoop for this). Place meatballs on prepared pan. Bake for about 15 minutes, or until meatballs are cooked through.
Remove from oven. Leave oven turned on.
for the sautéed veggies:
While meatballs are in the oven, heat a large skillet over medium to medium-high heat. Add oil.
Once oil is hot, add green pepper, yellow pepper, and onion, stirring to coat. Sauté until vegetables are softened, about 7 to 9 minutes, stirring regularly. Remove vegetables to a plate. Return skillet to heat.
for the taco sauce:
Add oil to hot skillet. Once oil is hot, add garlic. Stir to coat. Sauté for 1 to 2 minutes, stirring occasionally. Add tomatoes, cumin, chipotle pepper, and black pepper, stirring to combine. Heat until bubbling, stirring regularly.
Then add meatballs to skillet, folding to coat. Let cook until meatballs are thoroughly warmed.
to assemble:
Place open rolls on a rimmed baking pan. Bake for 5 minutes, or until lightly toasted. Remove pan from oven, spoon a bit of taco sauce over the bottom of each roll, and then divide meatballs among rolls.
Top meatballs with remaining taco sauce, followed by the sautéed veggies and shredded cheese. Return pan to oven and bake for 5 to 10 minutes, or until sandwiches are thoroughly warmed and cheese is melted.
Serve subs hot, with any variety of your favorite taco condiments and toppings.
Nutrition information is automatically calculated by Spoonacular. I am not a nutritionist and cannot guarantee accuracy. If your health depends on nutrition information, please calculate again with your own favorite calculator.