Warm the oil in a large salute pan or braiser over medium heat. Add white and light green portions of the green onion, garlic, and ginger; saute for 60 to 90 seconds, stirring frequently.
Add the tomato paste and gochujang; mix well and sauté for an additional 1 to 2 minutes, until the pastes begin to stick to the bottom of the pan.
Add the coconut milk, sugar, and gochugaru (if using) to the pan and whisk well, until the tomato paste and gochujang have dissolved into coconut milk to form a sauce.
Carefully add the chickpeas to the sauce and mix well. Bring the mixture to a simmer over high heat. Reduce heat to medium-low and maintain the simmer, stirring occasionally, for 12 to 15 minutes, or until the sauce has thickened to your liking.
Stir in toasted sesame oil at end of cooking.
Turn the heat off and stir in the toasted sesame oil. Serve the hot gochujang chickpeas over cooked rice (or as desired) and top with the reserved dark green portions of the green onion, gochugaru, and toasted sesame seeds.
