Preheat the oven to 140°C (284°F). Line a baking sheet with parchment paper.
Wash and peel the carrot, parsnip, beetroot, and sweet potato as desired.
Using a mandoline set to a thin setting (level 2–3), slice the vegetables into even thin slices.
Arrange the slices in a single layer on the prepared sheet without significant overlap.
Drizzle the vegetable slices lightly with 1 tsp olive oil and sprinkle with sea salt if using.
Bake for 25–30 minutes at 140°C, turning once if needed, until the slices are crisp and edges are browned. Remove and cool.
Make the sriracha yogurt: stir 2 tbsp Greek yogurt with 1 tsp sriracha until smooth.
Make the curry-cumin yogurt: stir 2 tbsp Greek yogurt with 1/2 tsp curry powder and 1/4 tsp cumin until combined.
Make the olive oil yogurt: stir 2 tbsp Greek yogurt with 1 tsp olive oil and a pinch of salt.
Make the dried tomato yogurt: stir 2 tbsp yogurt with 2 finely chopped dried tomatoes.
Make the pesto yogurt: stir 2 tbsp Greek yogurt with 2 tsp pesto until smooth.
Make the tzatziki: grate and squeeze half a small cucumber, then mix with 2 tbsp Greek yogurt, 1 sprig chopped dill, 1/4 clove crushed garlic, and salt and pepper to taste.
Serve the cooled veggie chips with the six prepared yogurt dips.