01 - Preheat oven to 425°F and line a baking sheet with parchment paper.
02 - Toss cauliflower florets and red bell pepper with 1 tablespoon olive oil, a pinch of salt, and ground turmeric. Arrange on the prepared baking sheet in a single layer. Roast for 25 to 30 minutes, turning once halfway, until browned and tender.
03 - Combine jasmine or basmati rice, water, and 1/2 teaspoon salt in a saucepan. Bring to a boil over high heat, then reduce heat to low, cover, and simmer for 12 to 15 minutes until the rice is tender and water is absorbed. Remove from heat and fluff with a fork.
04 - In a large skillet or wok, heat the remaining 1 tablespoon olive oil over medium heat. Add the chopped onion, minced garlic, and grated ginger, then sauté for 2 to 3 minutes until fragrant and translucent.
05 - Add red curry paste to the skillet and stir for 1 minute. Pour in coconut milk and soy sauce, stirring well. Allow to simmer for 3 to 4 minutes until slightly thickened.
06 - Add roasted cauliflower and red bell pepper to the curry sauce. If using, stir in baby spinach until just wilted. Squeeze lime juice into the mixture and stir well.
07 - Spoon steamed rice onto plates and ladle the red curry with vegetables over the top. Garnish with chopped cilantro, lime wedges, and toasted cashews or peanuts if desired.