Heat the vegetable oil in a large pot over medium heat. Add the chopped onion and cook until translucent. Add the minced garlic and cook for another minute until fragrant.

Increase the heat to medium-high and add the ground beef, breaking it apart with a spoon. Cook until browned and no longer pink.

Stir in the chili powder, cumin, smoked paprika (if using), diced tomatoes (with their juice), and kidney beans (if using). Season with salt and pepper to taste.

Reduce the heat to low and let the chili simmer, uncovered, for about 20-30 minutes to allow the flavors to meld. Adjust the seasoning as needed.

While the chili simmers, cook the elbow macaroni according to the package instructions until al dente. Drain and set aside.

In a separate pot, melt the butter over medium heat. Stir in the flour to create a roux, cooking for about 1-2 minutes.

Gradually whisk in the milk, ensuring there are no lumps. Continue to cook, stirring constantly, until the sauce thickens.

Remove from heat and stir in the shredded cheddar cheese until melted and smooth. Season with salt and pepper to taste.

Add the cooked macaroni to the cheese sauce, stirring until well coated.

Serve the chili over a bed of the cheesy macaroni. Alternatively, you can mix the chili and cheesy macaroni together before serving for a fully integrated dish.

Serve the Texas Chili Mac hot, garnished with additional shredded cheese, chopped onions, or fresh cilantro if desired.