Adjust rack to top position and preheat oven to 450 degrees. Wash and dry produce.

Heat a large dry pan over medium-high heat. Add bacon*; cook, turning occasionally and adjusting heat if browning too quickly, until crispy, 6-10 minutes. Turn off heat; transfer to a paper-towel-lined plate. Wipe out pan and let cool slightly.

Meanwhile, halve tomato lengthwise and thinly slice into half-moons. Halve, peel, and thinly slice shallot. Peel and mince or grate garlic.

In a small bowl, combine tomato, shallot, garlic, balsamic vinegar, ¼ tsp sugar, and a pinch of Italian Seasoning (½ tsp sugar and a big pinch of Italian Seasoning for 4 servings). Set aside to marinate.

Pat chicken* dry with paper towels; place between two large pieces of plastic wrap. Pound with a mallet or rolling pin until chicken is about ½ inch thick. Season with remaining Italian Seasoning, a pinch of salt, and pepper.

Heat a drizzle of oil in pan used for bacon over medium-high heat. Add chicken; cook until browned and cooked through, 3-5 minutes per side.

Meanwhile, place flatbreads on a baking sheet. Toast on top rack, flipping halfway through, until golden, 3-4 minutes. Transfer to a cutting board; halve crosswise.

In a second small bowl, combine basil paste and mayonnaise.

Pour balsamic mixture from tomato salad into two small serving bowls (four for 4 servings). Add 1 tsp olive oil to each bowl; stir to combine.

Spread flatbreads with basil mayo. Fill with bacon, chicken, and as much tomato salad as you like. Close sandwiches and halve crosswise.

Divide any remaining tomato salad between bowls. Divide sandwiches between plates. Serve with balsamic dipper on the side.