Wash and dry all produce. Take out 4 TBSP butter and let soften at room temperature. Halve, peel, and slice onions. Dice tomatoes. Halve cucumbers lengthwise, then slice crosswise into half-moons.

Heat a drizzle of olive oil in a medium pan over medium-high heat. Add onions. Cook, tossing, until softened, about 5 minutes. (TIP: Add a splash of water if it burns.) Stir in 2 tsp sugar and cook until just browned, 3-5 minutes. Pour in 2 TBSP vinegar (we’ll use more later) and let evaporate, about 1 minute. Season with salt and pepper.

While onions cook, tear pork into bite-sized pieces with your hands. Heat a large drizzle of vegetable oil in a large pan over medium-high heat (use a nonstick pan if you have one). Add pork and a big pinch of salt and pepper. Cook, tossing occasionally, until beginning to crisp, 5-6 minutes. Remove from pan and set aside; wipe out pan.

In a small bowl, toss together tomatoes, cucumbers, remaining vinegar, and a drizzle of olive oil. Season with salt and pepper. Set aside. Lower heat under pan used for pork to medium and add a drizzle of vegetable oil. Spread butter in a thin layer on one side of each bread slice, using about 1/2 TBSP per side.

Place 4 bread slices buttered-side down on your cutting board and top each with cheddar, pork, and onion jam. Place remaining slices on top, butteredside up, creating sandwiches. Add sandwiches to pan and toast until bread is golden brown and cheese melts, 2-4 minutes per side. TIP: Work in batches if you can’t fit all of the sandwiches (or use the pan used for onions as well).

Cut sandwiches in half and divide between plates. Serve with salad on the side.