How to Make It
Light a grill or preheat the broiler. Roast the poblanos over the grill or under the broiler, turning, until blackened, 3 to 4 minutes. Transfer to a bowl, cover with plastic wrap and let cool. Peel, core and seed the poblanos then finely chop them.
Brush the portobello mushrooms with 3 tablespoons of the olive oil and season with salt and pepper. Grill or broil the mushrooms over high heat, turning, until softened, 10 to 12 minutes. Transfer to a plate, stem side down; let drain and cool.
Meanwhile, in a medium skillet, heat the remaining 1 teaspoon of olive oil. Add the onion and cook over moderate heat until softened, about 6 minutes. Add the baby spinach and cook until wilted, about 1 minute. Transfer the spinach to a sieve and press out the liquid. In a bowl, mix the spinach with the rice, cheese, cilantro and poblanos. Season with salt and pepper.
Preheat the oven to 325°. Season the mushroom caps with salt and pepper. Spoon the rice mixture into the mushrooms, mounding it slightly. Transfer the mushrooms to a baking dish and bake for about 20 minutes, or until the cheese is melted and the top is lightly browned. Serve warm or at room temperature.
One Serving 214 cal, 15 gm total fat, 3.4 gm saturated fat, 18 gm carb, 5 gm fiber.