Preheat the oven to 425 degrees F.
Heat the olive oil in a large, oven safe skillet. When the oil shimmers, add the ground meat and brown all over, about 5 to 8 minutes. Reduce the heat to low, add the bell pepper, garlic, oregano, thyme, fennel, crushed red pepper flakes, and a pinch each of salt and pepper. Cook 5 minutes, until fragrant. Reduce the heat to low. Add the tomatoes and simmer 10 minutes or until the sauce thickens slightly.
Meanwhile, bring a large pot of salted water to a boil and boil the pasta until al dente. Drain and run under cold water to stop the cooking.
In a medium bowl, combine the ricotta, fontina, ½ cup pesto, and sun-dried tomatoes.
To assemble, spoon about 2 tablespoons of the cheese mix down the length of the noodle. Roll into a coil and place each seam-side down in the skillet as you go, snuggling the roll into the sauce. Repeat with remaining noodles. Drizzle the remaining ¼ cup pesto evenly over everything. Add the mozzarella.
Transfer the skillet to the oven and bake 15-20 minutes or until the cheese has melted and is lightly browned on top. Cool 5 minutes before serving. Serve with fresh basil and thyme, if desired.
