Bring a medium pot of salted water to a simmer. Add the halved/diced new potatoes and simmer until just tender when pierced with a knife (8–10 minutes depending on size). Parboiling the potatoes shortens pan time and ensures a soft interior before you crisp them—this way you get a golden crust without a raw center.

While the potatoes simmer, toss the cubed extra-firm tofu with the cornstarch, 1/2 tsp salt and 1/4 tsp black pepper in a shallow bowl. The cornstarch dry-coats the tofu and pulls moisture from the surface, which allows it to form a golden, crunchy crust when pan-fried.

Make the lemon-dill yogurt: in a small bowl combine the plain Greek yogurt, lemon zest, lemon juice, half the chopped dill (2 tbsp), 1 tsp chopped chives/parsley, 1/4 tsp salt and a few grinds of black pepper. Stir until smooth and refrigerate. Making the sauce first lets flavors meld and keeps it chilled so it contrasts with the hot hash.

Drain the parboiled potatoes and let them steam-dry in the colander for 2 minutes; rough the surfaces by shaking the colander or tossing gently—this creates extra surface area for crisping. Pat the potatoes dry with a kitchen towel so excess surface moisture doesn't steam in the pan.

Heat a large heavy skillet (cast-iron preferred) over medium-high heat. Add 3 tbsp olive oil. When the oil shimmers, add the potatoes in a single layer. Sprinkle with smoked paprika and 1/2 tsp salt. Let them cook undisturbed for 4–5 minutes to develop a deep golden crust, then turn and brown the other sides for another 4 minutes. Browning (Maillard reaction) builds complex savory flavors and gives the dish its irresistible texture.

Push the potatoes to one side of the pan and add 1 tbsp oil to the empty side. Add the prepared tofu cubes in a single layer, spacing them so the pieces don't touch (crowding causes steaming, not crisping). Cook undisturbed for 3–4 minutes until the bottoms are deeply golden, then turn and brown on at least two other faces so each cube has a crisp exterior. Use medium-high heat; if the tofu browns too quickly, lower the heat slightly—the goal is a crisp exterior and a creamy interior.

When the tofu is crisp and the potatoes are golden, stir the tofu and potatoes together. Add the remaining 2 tbsp olive oil (or a splash more if the pan looks dry), the minced garlic and the remaining chopped dill. Cook, tossing for 1–2 minutes until the garlic is fragrant but not burned—this layers bright aromatics into the hash. Taste and adjust seasoning with salt and pepper.

If using baby spinach, remove the pan from direct high heat and toss the spinach into the hot pan so residual heat wilts it just enough to soften without turning mushy (30–60 seconds). This preserves the fresh color and texture. Stir in the thinly sliced spring onions and most of the remaining chopped chives/parsley, reserving a little for garnish.

Plate the hash onto warmed plates. Dollop or spoon the chilled lemon-dill yogurt alongside or across the top, scatter the thin radish slices and remaining chives/parsley. Finish with an extra pinch of smoked paprika and a drizzle of olive oil if desired. The contrast of hot, smoky hash with cool, acidic yogurt creates a memorable balance.

Serve immediately so the tofu and potatoes keep their crisp edges and the yogurt remains cool. Leftovers: store components separately (yogurt refrigerated and tofu/potatoes in an airtight container); to re-crisp tofu and potatoes, roast at 200°C/400°F for 8–10 minutes.