1/2 cup jarred roasted red bell peppers, finely chopped
12 grape tomatoes, halved
1 tbsp organic unsalted butter
1 tbsp white whole-wheat flour
1/4 cup whole milk
1/4 cup crumbled goat cheese
2 tbsp fresh thyme leaves, optional
Preheat oven to 375°F. Line a large rimmed baking sheet with foil and mist with cooking spray.
Using a spoon, carefully remove mushroom gills and discard. Place mushrooms on prepared sheet, cap side down, and brush with 1 tbsp oil.
In a medium skillet on medium-high, heat remaining 1 tbsp oil. Add garlic and cook, stirring constantly, until fragrant, about 30 seconds. Add zucchini and cook, stirring frequently until golden, about 3 to 4 minutes. Add spinach and cook, stirring frequently, until wilted, about 1 minute more. Place spinach mixture on top of each mushroom, dividing evenly. Sprinkle each mushroom with 1 tbsp bread crumbs. Top with red peppers and tomatoes, dividing evenly.
Prepare sauce: In a small saucepan, melt butter over medium heat until foamy. Add flour and stir constantly for 30 to 45 seconds. Slowly add milk, stirring constantly and cook until slightly thickened, about 1 minute. Remove from heat and stir in cheese until melted.
Divide sauce evenly between mushrooms and bake until mushrooms are softened and sauce is golden, about 15 minutes. Garnish with thyme (if using).