Thinly slice the onions. Peel the potatoes and cut into 2cm chunks. Put the potato in a medium saucepan of cold salted water, bring to the boil and cook over medium heat for 8 mins or until almost tender. Drain. Rinse and reserve the pan.
Step 2 — Prep ingredients
Meanwhile, pick the coriander leaves and finely chop the stems. Crush or finely chop the garlic. Thinly slice the chilli (add the chilli to the curried lentils to suit your heat preference). Drain and rinse the lentils.
Step 3 — Start curried lentils
Heat 1 tbs extra virgin olive oil in a separate medium saucepan over medium heat. Cook half the onion and half the chilli, stirring, for 3 mins or until softened. Add 2 tsp curry powder and cook, stirring, for 30 secs. Add the tomatoes, coriander stems, ½ tsp sugar and 60ml (¼ cup) water and bring to a simmer. Cook, stirring, for 10-12 mins until thickened.
Step 4 — Start golden potatoes
While the tomato mixture is cooking, heat 1 tbs extra virgin olive oil in the reserved pan over medium-high heat. Cook the remaining onion, stirring, for 5 mins or until the onion is softened and starting to brown around the edges.
Step 5 — Finish golden potatoes
Add the garlic, potato, remaining curry powder and ½ tsp turmeric* to the onion and cook, stirring, for 30 secs or until fragrant. Add 60ml (¼ cup) water and cook, stirring occasionally, for 3 mins or until the water is evaporated. Taste, then season with salt and pepper.
Step 6 — Get ready to serve
Stir the lentils and spinach into the tomato mixture. Cook, covered, for 1-2 mins until the spinach is wilted. Taste, then season with salt and pepper. Divide the curried lentils and golden potatoes among bowls. Scatter over the cashews, coriander leaves and remaining chilli. Serve with the yoghurt.