Heat your oven to 200°C/Fan 180°C/Gas 6. Peel the sweet potatoes. Slice into chunky chips. Tip into a bowl. Toss with 1 tbsp oil and some salt and pepper. Spread out on a baking tray. Bake for 30-35 mins till golden and cooked through.
Warm a frying pan over a medium heat. Add 1 tsp coriander seeds. Toast for 2 mins till they smell aromatic. Tip into a mortar and roughly crush them with a pestle, or use a small bowl and a jam jar to roughly crush them.
Slice the fat cheeks off the mango, then slice off the flesh on the narrower sides of the mango. Slice the flesh off the skin. Chop into small cubes. Pop them into a bowl.
Peel and finely dice the red onion. Add to the mango. Dice the tomato to match and add it to the bowl. Halve the chilli. Flick out the seeds and white pith for less heat. Finely chop it and add to the bowl with the crushed coriander seeds.
Finely chop the parsley, leaves and stalks. Add it to the bowl with 1 tbsp red wine vinegar. Add a pinch of salt and stir to mix. Set the salsa aside.
Whisk the remaining 1 tbsp red wine vinegar with 1 tbsp olive oil and some salt and pepper to make a dressing. Toss with the salad leaves and set aside.
Heat ½ tbsp olive oil in the frying pan. Add the gammon steaks. Fry them for 8 mins till golden on one side. Flip. Fry for another 5-8 mins on the other side till the steaks are cooked right through.
Serve the gammon steaks on warm plates with the salad, sweet potato chips and mango salsa.