Put the baby potatoes onto a large baking sheet and put them into the oven. Set oven to Steam, 212°F/100°C (100% humidity), and cook until the potatoes are tender when pierced with a small knife. This could take up to about 45 minutes depending on the size of your potatoes.
2 lb baby potatoes
When the potatoes are done, remove them from the oven and change the oven settings to Convection, 400°F/200°C (no steam). If the baking sheet has residual water in it, drain this off. Toss the potatoes in half of the olive oil to coat.
4 Tbsp olive oil
Using the base of a jar or glass, gently press down on the potatoes until they are squashed, but in one piece. They should be about a centimetre thick, with lots of rough edges, and with a little space around each one to allow for good airflow and crisping.
Drizzle the squashed potatoes evenly with the remaining olive oil and season generously with salt. Bake until crispy, about 30 minutes. Remove from the oven and let cool for 10 minutes.
1 tsp flaky salt, 4 Tbsp olive oil
While the potatoes are roasting, make the dressing. In a large bowl, whisk together the yogurt, mayonnaise, dill, parsley, shallot, garlic, Dijon, red wine vinegar, salt, and pepper. Scoop about a third of the dressing out and spread it over the base of a large serving platter.
3/4 cup Greek yogurt, 1/4 cup mayonnaise, 1/4 cup chopped dill fronds, 1/4 cup chopped flat-leaf parsley, 1 shallot, 1 garlic clove, 2 tsp Dijon mustard, 3 Tbsp red wine vinegar, 1/2 tsp flaky salt, 1/2 tsp ground black pepper
When the potatoes have cooled to warm, reserve the crispiest ones as a garnish, then add the rest to the bowl with the remaining dressing. Add the cucumber and pickles and toss everything gently until well coated. Taste and season with extra salt and pepper, if necessary.
1 cucumber, 1/3 cup cornichons
Pile the salad on top of the dressing on your serving platter, and top with the extra crispy potato bits to finish. Serve the salad immediately to maximise the texture of the smashed potatoes.