Peel the potatoes, dice them into small chunks, and boil in salted water for about 15 minutes until tender. Drain and mash until smooth, setting aside to cool slightly.
Finely chop or grate the mixed vegetables—carrots, peas, bell peppers, and spinach—then squeeze out any excess moisture to prevent sogginess.
In a large mixing bowl, combine the mashed potatoes and vegetables. Add cumin, coriander, garam masala, grated ginger, minced garlic, and lemon juice. Mix thoroughly until evenly incorporated.
Stir in chickpea flour or breadcrumbs gradually, mixing until the mixture is cohesive enough to shape. If it feels too wet, add a bit more flour; if too dry, a splash of water or lemon juice can help.
Shape the mixture into small, flat patties about 2.5 centimeters (1 inch) thick and uniform in size for even frying.
Heat vegetable oil in a frying pan over medium heat until shimmering and hot, around 160°C (320°F). Carefully place the tikkis into the hot oil, giving enough space between each.
Fry the tikkis for about 4-5 minutes per side, flipping gently with a spatula once they turn golden brown and crispy around the edges. Listen for a gentle crackle and smell the fragrant spices as they fry.
Remove the cooked tikkis from the pan and drain on paper towels to absorb excess oil. Rest for 2 minutes to allow the exterior to set and crisp up further.
Serve the hot, crispy vegetable tikkis with mint chutney or yogurt for dipping, enjoying their warm, tender interior and crunchy exterior.
