Pull the leaves and silks from the sweetcorn cobs. Slice a sliver off the bases of the cobs, so they stand upright on your chopping board, then run your knife down the cobs to remove the kernels.
Warm a large pan on a medium heat for 2 mins. Add the kernels and toast for 3-4 mins, stirring, till lightly browned. Tip into a bowl. Set aside.
Peel and finely chop the onion. Halve the pepper and scoop out the seeds and pith. Finely chop the pepper. Peel and dice the potato. Add ½ tbsp olive oil to the empty pan. Add the veg. Cook on a low heat, stirring, for 8 mins till starting to soften.
While the veg cook, peel and finely chop the garlic. Halve the chilli and finely chop it, removing the seeds and white pith for less heat.
When the veg have softened, add 2 tsp cumin seeds, the garlic, chill and a pinch of salt and pepper. Fry, stirring, for 2 mins. Add most of the corn back to the pan (keep a pinch back) and stir. Pour in the milk and 200ml cold water. Simmer on a low heat for 15 mins, till the veg are soft.
Finely chop the parsley leaves and stalks. When the veg are soft, stir in most of the parsley. Taste and season with salt and pepper. Ladle half the soup into a blender and blitz till smooth or use a hand-held blender in the pan, pulsing to half-blend the soup (or leave it chunky if you prefer).
Ladle the chowder into 2 warm bowls. Crumble a quarter of the feta over each. Top with the parsley leaves and a crack of black pepper to serve.