• Before starting, preheat oven to 450˚F.
• Remove 1 tbsp (2 tbsp) butter from the fridge and set aside to come up to room temperature.
• Wash and dry all produce.
• Remove brown spots from potatoes, then cut potatoes into 1/2-inch wedges.
• To an unlined baking sheet, add potatoes and 1 tbsp oil. (NOTE: For 4 servings, use 2 baking sheets, with 1 tbsp oil per sheet.) Season with salt and pepper, then toss to coat. 
• Roast in the middle of the oven for 24-26 min, flipping halfway through, until tender and golden. (NOTE: For 4 servings, roast in the middle and bottom of the oven, rotating sheets halfway through.)

• Meanwhile, cut bacon, cut strips in half crosswise. Heat a large non-stick pan over medium.
• When hot, add bacon. Cook for 5-7 min, flipping occasionally, until crispy.**
• Remove from heat. Using tongs, transfer bacon to a paper towel-lined plate. Set aside.
• Heat a medium pot over medium. 
• While the pot heats, peel, then cut onion into 1/4-inch slices.
• When the pot is hot, add 1/2 tbsp (1 tbsp) butter, then swirl the pot until melted. (NOTE: Save softened butter for step 4.)
• Add onions. Cook for 6-8 min, stirring occasionally, until softened. 
• Add half the balsamic glaze and 1 tbsp (2 tbsp) water, then season with salt. Cook for 4-5 min, stirring occasionally, until onions are dark golden. 
• Remove the pot from the heat.

• Meanwhile, peel, then mince or grate garlic.
• Halve rolls.
• Tear bocconcini into bite-sized pieces.
• Cut 2 (4) slices from the thickest part of tomato. Transfer tomato slices to a paper towel-lined plate. Season both sides with salt, then set aside.
• Cut remaining tomato into 1/2-inch pieces.
• To a small bowl, add pesto and 1/2 tsp (1 tsp) garlic. (NOTE: Like things garlicky? Add more garlic!) Season with salt and pepper, then stir to combine. Set aside.
• To a large bowl, add remaining balsamic glaze and 1 tbsp (2 tbsp) oil. Season with salt and pepper, then whisk to combine.

• When potato wedges are almost done, arrange rolls on another unlined baking sheet, cut-side up.
• Spread 1 tbsp (2 tbsp) softened butter on cut sides, then season with pepper.
• Toast rolls in the top of the oven for 4-5 min, until lightly golden. (TIP: Keep an eye on rolls so they don't burn.)
• Transfer top rolls to a plate, leaving bottom rolls on the baking sheet.

• When potato wedges are done, remove the baking sheet from the oven, then switch the oven to high broil.
• Pat tomato slices dry with paper towels.
• Spread half the garlicky pesto on bottom rolls, then top with tomato slices. Season with salt and pepper. Top with bocconcini.
• Return assembled bottom rolls to the middle of the oven for 3-4 min, until bocconcini melts. (TIP: Keep an eye on rolls so they don't burn.)

• Meanwhile, roughly chop bacon. Sprinkle bacon over bocconcini melts.
• To the bowl with remaining garlicky pesto, add mayo, then stir to combine.
• To the bowl with vinaigrette, add arugula and spinach mix and chopped tomatoes, then toss to coat.
• Carefully stack caramelized onions, some crispy shallots and some dressed greens on melted bocconcini. Close melts with top rolls.
• Divide melts, potato wedges and remaining salad between plates.
• Sprinkle remaining crispy shallots over salad.
• Serve pesto aioli alongside for dipping.

If you've opted to add bacon, cut bacon strips in half crosswise. Heat a large non-stick pan over medium. When hot, add bacon. Cook for 5-7 min, flipping occasionally, until crispy.** Remove from heat. Using tongs, transfer bacon to a paper towel-lined plate. Set aside.

Roughly chop bacon. Sprinkle bacon over bocconcini melts.