Heat your oven to 180°C/Fan 160°C/Gas 4. Cut the tomatoes in half. Peel and slice the garlic.
Trim your beetroot. Coarsely grate it in a food processor or use a grater – you don’t need to peel it. Grate the new potatoes and sweet potato. Leave the skin on for maximum flavour.
Tip the veg into a bowl and add 1 tsp salt. Toss and leave to sit for 5 mins. Strip the leaves from the thyme. After 5 mins, squeeze out the excess water from the veg with your hands. Spread them out on a baking tray. This is your rösti.
Drizzle with 1 tbsp oil and the thyme leaves. Season. Bake for 30-40 mins till the veg is softened and crispy around the edges. Roughly chop the parsley leaves and set aside for later.
Put the tomatoes and garlic in a baking dish with 2 tsp of coriander seeds. Drizzle with 1 tbsp oil. Slide into the oven and roast for 20 mins above the rösti.
When the tomatoes are tender, blitz them in a food processor till smooth. Spoon in the tamarind paste with 2 tbsp cold water and pulse to combine. Alternatively, mash the tomatoes with a fork and press through a sieve for a smooth sauce. Season.
When the rösti is nearly cooked, fill a deep wide pan with boiling water. Crack one egg into a cup. Gently slide the egg into the water. Repeat with the rest of the eggs. Pop the lid on.
Very gently simmer for 2-3 mins till the whites are set and the yolk is cooked as you like it. Remove with a slotted spoon. Serve the rösti in slices topped with the poached eggs and tamarind tomato sauce. Sprinkle with the chopped parsley to garnish.