Warm the olive or avocado oil in a large skillet over medium-high heat.
Add the ground beef and diced onion, stirring frequently to break the meat apart, and cook until beef loses its pink color, about 7 minutes.
If necessary, drain any excess fat from the skillet.
Sprinkle in chili powder, cumin, oregano, salt, pepper, and mix in the tomato paste until the beef is well coated.
Pour in the brown rice pasta, diced tomatoes with green chiles, and chicken broth, stirring everything to combine evenly.
Bring the mixture to a rolling boil, then lower heat to maintain a gentle boil and cook, stirring occasionally, until the pasta is tender but still firm, around 13 minutes.
Turn off the heat and gently fold in the shredded cheese, if using, letting it melt slightly.
Allow the pasta to rest for a few minutes before serving.
Top with freshly chopped cilantro, avocado slices, jalapeno slices, and radishes for garnish.