Cook chutney ingredients for 10 minutes and process in a food processor.
Roast cauliflower at 400 degrees with 2 Tablespoons of oil and salt and pepper. Boil potatoes. Cook everything else except the peas in a skillet until soft and fragrant. Mash together with potatoes and cauliflower and then add peas.
Sauté onion until browned, add all the spices and cook till fragrant. Add beans, water, and tomatoes, salt and pepper. Simmer for 10 minutes. Mix in cilantro, brown sugar, and lemon juice. Pulse in a food processor.
Put a bit of each filling on a bun with a bit of spinach, brush with oil and grill.