Bring 4 cups of water to a boil in a medium-sized sauce pan.Add the rice and stir to combine. Reduce the heat to a low simmer and cook until the rice is soft, but still slightly chewy and the water has cooked off.Set aside.
Heat up a large stockpot. When hot, add the shiitake mushrooms and ¼ cup of water. Simmer the mushrooms until the water has almost cooked off. About 6-8 minutes. Add 1 tablespoon of the coconut oil and, keeping the heat at medium-low, sauté the mushrooms until they are just slightly crispy. Remove the mushrooms from the pan and set aside.
Add remaining tablespoon of coconut oil to the stock pot along with the scallion whites, garlic and ginger. Briefly sauté until fragrant. About 1-2 minutes. Be careful not to burn the ginger or garlic as they will become bitter.
Add the Thai red curry paste and stir to combine. Toast the red curry paste until it becomes fragrant. About 1-2 minutes.
Add the coconut milk, water, peanut butter and tamari. Whisk the broth until the red curry paste and peanut butter is fully dissolved. A miso whisk is particularly helpful here. See my What’s in My Kitchen to Make This Thai Red Curry Vegetables & Rice Recipe Easier section for more details.
Bring the broth to a simmer and add the mushrooms.
Prepare your serving bowls by adding the rice to the bowl. To make the rice island, pack the rice into a small serving dish (see my What’s in My Kitchen to Make This Thai Red Curry Vegetables & Rice Recipe Easier section for more details) and flip the small serving bowl upside-down into the center of the large serving bowl. Tap the bottom of the small serving bowl to release the rice.
Just before serving, add the broccolini, squash,zucchini and red pepper to the simmering broth. Continue to cook until the vegetables are bright in color but maintain their crispness. About 5 minutes. Serve immediately by spooning the broth around the rice island. Top with optional red chilies, lime wedges, fresh cilantro, mint leaves and chopped peanuts.