Wash and dry all produce. Preheat oven to 450 degrees. Halve, peel, and thinly slice red onion. Trim ends from zucchini, then peel on all sides into ribbons with a vegetable peeler, stopping before you reach seedy core. Discard core. Slice olives into rounds. Thinly slice sun-dried tomatoes.

Heat a drizzle of olive oil in a medium pan over medium-high heat. Add onion and 1 TBSP balsamic vinegar. Cook until caramelized, 3-5 minutes, stirring occasionally. Remove from heat.

Stir thyme into ricotta in a small bowl. Season generously with salt and pepper.

Place flatbreads on a lightly oiled baking sheet. Spread ricotta sauce on each flatbread in a thin layer. Top with zucchini, olives, sun-dried tomatoes, caramelized onions, and walnuts. Bake until zucchini is crisp and flatbreads are lightly browned, 10-12 minutes.

Combine 1 tsp Dijon mustard and 1 TBSP balsamic vinegar in a large bowl. Whisk in a drizzle of olive oil and season with salt and pepper. Add mixed greens and toss to combine.

Slice flatbreads into quarters. Serve with salad.