Ingredients
Method
Assembly and Baking
- Preheat the oven to 350°F. Lightly coat a 1 1/2- to 2-quart casserole dish (8-by-8 inches or 5-by-7 inches) with nonstick cooking spray.
- Heat the olive oil in a large skillet over medium heat.
- Add the sliced onion and cook, stirring occasionally, until softened and caramelized, about 4 to 5 minutes.
- Season with salt and pepper to taste, stir, and remove the skillet from the heat.
- Crush 3 ounces of the buttery round crackers and scatter them evenly across the bottom of the prepared dish.
- Spoon half of the canned fire-roasted tomatoes over the cracker layer.
- Spread half of the cooked onions over the tomatoes.
- Repeat with the remaining tomatoes and the rest of the onions to create a second layer.
- Crush another 3 ounces of crackers and sprinkle them over the tomato and onion layer.
- In a bowl, stir together the mayonnaise, shredded cheddar, grated Parmesan, and dried basil until well blended.
- Dollop the cheese mixture over the crumb layer in spoonfuls, then gently spread with a knife to cover the crumbs without pulling them up.
- Crush the remaining 1 ounce of crackers and sprinkle over the cheese mixture.
- Bake at 350°F for 30 minutes, until the top is golden and the casserole is bubbling around the edges.
- Let the casserole rest for 5 to 10 minutes before serving. Garnish with fresh basil leaves if desired.
Nutrition
Notes
Swap up to half of the mayonnaise with plain Greek yogurt for a lighter, tangier topping.
Assemble the casserole up to a day ahead; wait to add the final cracker layer until just before baking.
Store leftovers in an airtight container in the fridge for up to 4 days.
To reheat, place in a 350°F oven for about 10 minutes, which helps the crackers stay crisp.
Let the dish rest for 5 to 10 minutes after baking so the layers set and portions hold their shape.
Add a pinch of cayenne or a splash of hot sauce to the cheese mixture if you like a little heat.
Serve alongside roasted chicken, pork chops, or a fresh green salad.