Scrub the potatoes and chop them into bite-size pieces. Pop them in a pan. Cover with boiling water. Simmer for 15 mins till tender, then drain and leave to steam dry in the colander.
While the potatoes cook, snap the woody ends off the asparagus and discard them (if you bend the asparagus they will snap where the woody part of the stem ends). Trim the asparagus into 3cm-long chunks. Finely grate the zest from the lemon. Juice it. Set aside.
Trim the leeks. Slice the leeks in half lengthways and rinse out any grit. Halve again so you have 4 long lengths per leek. Slice them into long, fine, thin shreds. Put the leeks in a bowl. Add 1 tbsp cornflour and a little salt and pepper. Stir to mix them together. Set aside.
Measure out ½ tsp of the turmeric, 1 tsp of the cumin seeds, a pinch of chilli powder (it’s spicy so use as much or as little as you like) and 1 tsp garam masala into a small bowl. Add 1 tbsp oil and stir together. Put to one side.
Warm 100ml oil in a deep frying pan or wok for 2 mins over a medium heat. Add the leeks. Fry for 2-3 mins till golden and crisp. Lift out of the pan with a slotted spoon or tongs, onto a plate lined with kitchen paper. You’ll probably need to do this in 2-3 batches.
Pour the oil out of the pan and wipe it clean with kitchen paper. Add the spice paste. Stir and fry for 1 min. Add the asparagus and boiled potatoes. Stir and fry for 5 mins till the veg are charred and tender. Take off the heat. Stir in the lemon zest and juice. Set aside, with the lid on, to keep warm.
Bring a pan of water to the boil. Crack 2 eggs into separate cups. When the water is boiling, slide the eggs into the pan. Take it off the heat. Cover. Leave for 2-3 mins to poach the eggs (or cook for a little longer for set yolks). Lift the cooked eggs out of the pan and drain on kitchen paper while you poach the remaining 2.
Pile the fragrant spiced asparagus and potatoes onto 2 plates with the crisp leeks. Top with the poached eggs. Serve straight away.