Prep the Vegetables: Scrub or peel the potatoes, quarter them lengthwise, and slice thickly.
Boil in salted water for 5 minutes, then drain and set aside. Trim the green beans, cut them into 1-inch pieces, and boil in salted water for 5 minutes.
Drain and set aside.
Slice the zucchini thickly, boil in salted water for 3-4 minutes, drain, and set aside. Coarsely chop the fresh spinach and set it aside.
Build the Spice Base: Melt the butter in a large pot or Dutch oven over medium heat. Halve and thickly slice the onions, and crush or mince the garlic.
Sauté them in the butter until the onions soften and begin to turn golden.
Bloom the Spices: Add the turmeric, coriander, cumin, hot paprika, cayenne, black pepper, cinnamon, and salt to the pot.
Stir constantly for 1-2 minutes until the spices are fragrant.
Combine the Curry: Add the par-boiled potatoes, green beans, zucchini, and the fresh spinach to the pot.
Stir in the grated ginger, chopped green chilis, lemon juice, and water.
Simmer to Perfection: Mix everything thoroughly to coat the vegetables in the spices.
Bring to a simmer, then reduce the heat to low.
Cook, stirring occasionally, for 15-20 minutes, or until most of the water has evaporated and the vegetables are tender but not mushy.
