Preheat your oven to broil.
In a small bowl, mix together all the ingredients for the chimichurri: parsley, cilantro, red chili, oregano, garlic, olive oil, salt, black pepper, and vinegar. You can use it right away, but for even more flavor, let it sit for at least 30 minutes.
Slice the French bread loaf in half lengthwise. If you prefer, you can also trim off both ends of the loaf. Place both halves on a baking sheet lined with parchment paper.
Ensure the chimichurri is well mixed, then spread it lightly over each half loaf. Sprinkle as much or as little grated parmesan cheese on top as you like, and then layer on the shredded mozzarella. Add as much cheese as you desire.
Slide the baking sheet into the oven and broil on a middle rack. Keep a close eye on it to prevent burning. After 5 to 8 minutes, the cheese should be bubbly, and the edges of the bread golden brown and crispy.
Remove the tray from the oven, slice the loaves into triangles or rectangles, and savor every bite!