Caramelized Onions

1. Sauté thinly sliced yellow onion in olive oil or reserved bacon fat over medium-low heat.
2. Add a splash of water and cover early to steam and prevent burning.
3. Cook, stirring occasionally, 30–45 minutes until onions are soft, jammy, and golden; season with salt and fresh thyme.

Aioli

1. Mash the roasted garlic cloves in a bowl until smooth.
2. Stir in mayonnaise, chopped rosemary, a squeeze of lemon juice, and salt and pepper until creamy.

Arugula

1. Lightly salt tomato slices and set aside.
2. Toss arugula with a squeeze of lemon juice, a drizzle of olive oil, and a pinch of salt; set aside until assembly.

Main

1. Cut bacon in half and fry in a small pan over medium heat until evenly crisp; set aside and reserve the bacon fat.
2. In a cast-iron pan, toast both sides of the bread slices in a thin layer of reserved bacon grease until golden and crisp.
3. In bacon fat or a clean pan, fry the eggs over medium-high heat; season with salt and pepper and cook until whites are set but yolks remain runny.
4. Spread the aioli on both slices of toasted bread; layer caramelized onions, bacon, tomato slices, fried eggs, and havarti cheese. Optionally melt the cheese briefly under a broiler.
5. Top with the lemon-dressed arugula, close the sandwich, slice, and serve warm.