Begin by cooking your red potatoes until soft, either boiling for 15-20 minutes, microwaving for 8 minutes, or baking at 400°F for 45 minutes. Peel off the skins and set aside to cool slightly.

In a skillet over medium heat, add the avocado oil. Once hot, sauté the grated ginger and garlic for about 30 seconds until fragrant. Add the diced onion and cook for 2-3 minutes, stirring frequently.

Add the chopped cooked potatoes to the skillet. Sprinkle in turmeric, cumin coriander powder, red chili powder, salt, garam masala, and amchur powder, mashing the potatoes with a fork. Stir in frozen peas, cooking for another 3-4 minutes, and garnish with chopped cilantro.

Spread a thin layer of vegan mayo and green chutney on both slices of sourdough bread. On one slice, layer half of the spicy samosa filling, followed by slices of cheese. Top with remaining slice.

Heat a skillet over medium heat, spreading butter on the outer sides of the sandwich. Grill for about 4-5 minutes on each side until golden brown and crispy, and the cheese melts.

Once grilled, remove from skillet and let it rest for a minute. Slice in half and serve warm with extra chutney or yogurt.