Balsamic Glazed Portobello Steaks with Creamy White Bean Polenta

1. Marinate the Portobello Steaks

1. In a wide, shallow bowl, whisk together the balsamic vinegar, tamari, maple syrup, grated garlic, minced rosemary, olive oil, and a generous pinch of black pepper.
2. Place the cleaned portobello caps in the dish, turning them several times to coat thoroughly. Let them marinate at room temperature for 15 to 20 minutes, spooning extra liquid over them occasionally.

2. Prepare the High-Protein Polenta Base

1. Add the drained cannellini beans and milk to a blender or food processor. Blend until silky smooth and uniform.
2. In a medium saucepan, bring the vegetable stock and fine sea salt to a rolling boil over medium-high heat.
3. Gradually stream in the polenta while whisking continuously to prevent lumps from forming.
4. Lower the heat to low, cover the pan, and simmer for about 12 to 15 minutes, stirring every couple of minutes so the bottom does not scorch.
5. Fold the pureed white beans, butter, and grated cheese into the cooked polenta. Stir until rich, creamy, and thoroughly incorporated. Keep warm over very low heat, adding a splash of stock if it becomes too thick.

3. Sear and Glaze the Portobello Steaks

1. Heat a heavy skillet (preferably cast iron) over medium-high heat.
2. Lift the mushroom caps from the marinade, reserving the remaining liquid in the bowl.
3. Lay the portobellos topside-down in the hot pan. Sear for 4 to 5 minutes until browned and fragrant, then flip and cook for another 3 to 4 minutes.
4. Pour the reserved marinade directly into the pan around the mushrooms. Let the sauce bubble vigorously and reduce into a thick, glossy glaze, spooning it over the mushroom caps for 1 to 2 minutes until nicely lacquered and tender.

4. Plating

1. Spoon a generous circle of the hot, creamy white bean polenta into the center of each shallow serving bowl or plate.
2. Place one or two glazed portobello steaks on top of each polenta bed.
3. Drizzle any remaining pan reduction over the mushrooms and polenta.
4. Finish with a scatter of toasted walnuts and fresh microgreens.