Preheat your oven to 350°F. Line a baking sheet with parchment paper.
In a large skillet over medium-high heat, warm the oil. Add onion and cook until softened, about 3 minutes. Stir in ginger and garlic; cook 1–2 minutes more until fragrant.
Add all the spices and cook, stirring, for 30 seconds. Pour in the stock, then add roasted vegetables and peas. Simmer, stirring gently, until sauce thickens into a paste, about 3–5 minutes. Remove from heat.
Cut each pastry sheet into two 5½-inch circles. Place about ¼ cup filling in the center of each circle. Fold into a half-moon, seal edges with a fork, and transfer to the prepared sheet.
Whisk together the mayo, plant milk, and pinch of salt. Brush atop each pasty. Bake 35–40 minutes, until golden brown, checking after 35 minutes and adding time if needed.
Let cool slightly. If desired, serve with chili oil, lime wedges, and a side of coconut yogurt.