Cook the rice according to package directions. Cover and let rest until ready to serve.
Heat a large skillet with deep sides over medium heat. Once hot, add the canola oil. Cook the onion, ginger and garlic for about 5 minutes, stirring often. Add the green beans and carrots and cook for 3 more minutes, stirring occasionally.
Add curry paste and cook, stirring often, for 2 minutes.
Pour the coconut milk into the pan, along with 1/2 cup water and 1 1/2 teaspoons sugar. Bring the mixture to a simmer. Reduce heat as necessary to maintain a gentle simmer and cook until the carrots and green beans are tender and cooked through, about 5 to 10 minutes.
Once the vegetables are done cooking, stir the spinach into the mixture and cook until the spinach has wilted, about 30 seconds. Remove the curry from heat and season with rice vinegar and soy sauce. Add red pepper flakes, to taste.
Divide rice and curry into bowls and garnish with chopped cilantro.