Before starting, remove 1 tbsp butter (dbl for 4 ppl) from the fridge and set aside to come up to room temperature. Preheat the broiler to high. Wash and dry all produce. Peel, then cut onion into 1/8-inch slices. Heat a medium pot over medium heat. When hot, add 1/2 tbsp butter (dbl for 4 ppl), then onions. Cook, stirring occasionally, until golden-brown, 5-7 min. Add half the balsamic glaze and season with salt and pepper. Cook, stirring occasionally, until onions are dark golden-brown, 2-3 min. Remove the pot from heat.

While onions caramelize, core, then cut pear into 1/4-inch slices. Cut tomato into 1/2-inch pieces. Halve rolls. Add remaining balsamic glaze and 1/2 tbsp oil (dbl for 4 ppl) to a large bowl. Season with salt and pepper, then whisk to combine. Cut brie into 1/4-inch slices.

Heat a large non-stick pan over medium-high. When hot, add 1/2 tbsp butter (dbl for 4 ppl), then swirl the pan until melted. (NOTE: Do not use the softened butter in this step; save it for step 4.) Add pears, then sprinkle with 1/4 tsp sugar (dbl for 4 ppl). Cook pears, stirring occasionally, until warmed through, 1-2 min. Transfer pears to a plate to cool.

Arrange bottom rolls on a foil-lined baking sheet, cut-side up. Broil in the top of the oven until golden-brown, 1-2 min. (TIP: Keep an eye on rolls so they don't burn!) While bottom rolls toast, spread softened butter on top rolls.

Spread Dijon on toasted bottom rolls. Top with pears, caramelized onions, then brie. Arrange assembled bottom rolls and buttered top rolls, on the same foil-lined baking sheet, cut-side up. Broil in the middle of the oven until brie is warm and top rolls are golden-brown, 3-5 min. (TIP: If you want meltier brie, remove top rolls from the oven once they're golden-brown and continue broiling bottom rolls until desired doneness.)

Add spinach and tomatoes to the large bowl with vinaigrette. Toss to combine. Spread fig spread on top rolls, then close assembled melts. Cut in half crosswise, if desired. Divide melts and salad between plates. Sprinkle salad topping mix over salad.