Measure out 7/8 cup hot water in a large jug, add the peanut butter and stir until it dissolves. Stir in the tomato paste, lime zest and juice, Thai fish sauce and soy sauce.
Remove the leaves from the cilantro and set aside. Chop the stalks and roots as finely as possible and mix with the chopped chili peppers, garlic and ginger.
Heat the oil in a large pan and fry the onions over a high heat for a few minutes until they start to soften and slightly brown.
Add the carrots and fry for 2 minutes, followed by the squash. Fry for a further 2 minutes.
Sprinkle over the chili mixture, cook for one minute and pour over the coconut milk and the peanut butter mixture. Simmer until the liquid has reduced a little and the vegetables are tender – about 25 – 30 minutes.
For the last minute add the spinach, allowing it to wilt a little. Season to taste, sprinkle with the coilantro leaves and chopped roasted peanuts. Serve.