Ingredients, serves 25+, scale as needed:
3 large red bell peppers, seeded and cut in to chunks
6 garlic cloves, smashed with back of knife, divided
1 ½ cups panko
9 TBSP butter, room temperature, divided
1 ½ cup freshly grated parmesan cheese, divided
2 cups sliced pimientos, drained
¾ tsp ground chipotle pepper
3 ¾ cups (packed) coarsely grated extra-sharp cheddar
3 cups (packed) coarsely grated mozzarella
24 ounces shell pasta
Salt to taste
Cooking spray (or more butter)
Bring ¾ cup water to boil and add bell pepper and 4 garlic cloves; cover and cook over med-low for 15 minutes, until pepper is soft. Drain and set aside to cool.
Toast panko in skillet over med-high heat, watching carefully and stirring often, until browned (about 5 minutes). Remove to a bowl and let cool.
When pepper mixture has cooled add it to bowl of food processor along with pimientos, 6 TBSP butter, chipotle pepper, and remaining garlic. Pulse to mix all together then add cheddar and ¾ cup parmesan and blend until smooth. Taste and add salt as needed.
Preheat oven to 400 degrees.
When panko is cool, mix remaining butter in with fingers to coat crumbs. Mix in remaining parmesan.
Put water on to boil to cook pasta. Spray large casserole dish with cooking spray, or use more butter (I used a 9x15x3 inch dish and it was very full!). When water is boiling, cook pasta just until al dente, drain and place in large mixing bowl. Add sauce and mozzarella; taste and add more salt if needed. Spoon into prepared casserole dish and sprinkle with panko topping.
Bake until sauce is bubbling and top is crispy. In my oven this was 35 minutes. Serve hot.