Heat 2 tablespoons of the oil in a medium paella pan over high heat until it begins to shimmer. Add the mushrooms and cook until golden brown. Remove to a plate. Add more oil to pan, if needed, add the onions, red and poblano pepper and cook until soft, about 5 minutes. Add other half of the garlic and cook for 30 seconds. Stir in the rice and cook, stirring constantly, for a few minutes or until the rice is translucent. Add the wine and cook until completely reduced. Stir in 4 cups of the stock, salt and pepper, the mushroom and thyme and cook, stirring occasionally, until the rice is al dente and a crust (soccorate) has formed around the sides and bottom. Stir in the kale and cook until just wilted, about 5 minutes.