Fill a large pan with water and bring to the boil. Peel the red onion and thinly slice it. Slide the red onion into a bowl. Grate in the lime zest and squeeze in the juice. Add a pinch of salt and pepper. Scrunch the onions and lime together and set aside while you prepare everything else.
Peel and crush or finely chop the garlic cloves. Halve the chilli, flicking out the seeds and membrane for less heat. Finely chop the chilli. Pull the silks and leaves off the corn cob. Slice a sliver off the base so it sits upright on your chopping board. Run a knife down the cob to slice off the sweetcorn kernels. Halve the cherry tomatoes. Drain and rinse the black beans.
Pour 1 tbsp oil into a medium pan and warm to a medium heat. Slide in the corn kernels, along with the chilli, garlic and 2 tsp ground cumin. Sprinkle in a pinch of salt and pepper. Fry for 5 mins, stirring occasionally, till the corn is golden and tender.
Pour the drained beans into the pan. Slide in the cherry tomatoes. Warm through for 5 mins.
The water in the other pan should be boiling by now. When you’re nearly ready to serve, set the heat to medium-low so it’s just boiling – you only need a few bubbles. Crack 1 egg into a small cup. Carefully slide it into the water. Repeat with the other eggs. Gently cook for 2-3 mins for a runny yolk or 3-4 mins for a more set yolk.
Spoon the beans and corn onto plates. Top with the poached eggs. Top with the pickled onions and their limey liquid. Scatter over the rocket leaves and serve.