Heat a tablespoon of oil in your medium saucepan over medium heat until shimmering and fragrant. Add the cumin seeds and toast for about 30 seconds until they crackle and release their aroma.
Add the finely chopped onion to the pan and cook, stirring occasionally, until translucent and just beginning to turn golden, about 5 minutes. The kitchen will fill with a sweet, caramelized smell.
Stir in the minced garlic and ginger, cooking for another 1-2 minutes until fragrant. Be careful not to burn the garlic; the mixture should smell warm and spicy.
Add the turmeric and ground coriander to the pan, stirring well to coat the aromatics. Let them toast for about 30 seconds until fragrant, which deepens their flavor.
Pour in the coconut milk, stirring to combine with the spices and aromatics. Bring the mixture to a gentle simmer, allowing the flavors to meld and the sauce to warm through.
Add the frozen green peas directly from the freezer into the sauce. Stir well, then let everything simmer gently for about 5 minutes until the peas are tender and the sauce slightly thickened.
Check the seasoning and add salt to taste. Squeeze in the lemon or lime juice to brighten the flavors, then stir to combine. The sauce should be creamy and vibrant green.
Remove the curry from heat and let it rest for a couple of minutes. The sauce will thicken slightly and the flavors will meld beautifully. Serve hot with rice or bread for a cozy, satisfying meal.
