There's savory umami flavors and then there's this: a marsala-mushroom combo that'll knock your socks off and leave you begging for more. Soft, sweet acorn squash is roasted, then garnished with the unmistakable flavors of blue cheese and almonds. But the star is the sauce: dried porcini mushrooms and marsala marry to form a rich sauce perfect for chicken (and anything else you want to put it on).
Trim ends off squash and halve from pole to pole. Use a spoon to scoop out strings and seeds. Place halves, cut-side down, on cutting board and make 1" slices across its length, creating crescents. Place on prepared baking sheet and toss with 2 Tbsp. olive oil and ½ tsp. salt, using your hands to coat squash. Spread into a single layer and bake, flipping after 20 minutes, until squash is tender and well-browned, 25-30 minutes. While squash roasts, prepare ingredients.
Prepare the Ingredients
Cover dried mushrooms with 1 cup warm water in a small bowl. Trim and thinly slice green onions on an angle, keeping white and green portions separate. Coarsely chop almonds. Rinse chicken breasts, pat dry, and season both sides with ¼ tsp. salt and a pinch of pepper.
Cook the Chicken
Heat a medium pan over medium heat. Add 2 tsp. olive oil and chicken to hot pan and cook until chicken is deep brown and reaches a minimum internal temperature of 165 degrees, 4-6 minutes per side. Transfer chicken to a plate. Reserve pan; no need to wipe clean.
Prepare the Mushrooms
Remove hydrated mushrooms from water (reserve soaking liquid) and coarsely chop.
Make the Sauce
Return pan used to cook chicken to medium heat. Add white portions of green onions and mushrooms to hot pan and cook until fragrant, 1 minute. Add marsala and cook 1 minute. Add almost all soaking liquid (leave any sediment from mushrooms in the bowl) and chicken demi-glace to pan and cook until reduced by half, 4-5 minutes. Remove from burner and swirl in butter to enrich sauce.
Plate the Dish
Arrange chicken and squash on plate. Pour sauce over chicken and garnish squash with blue cheese, green portions of green onions, and almonds. Roasted acorn squash skin is edible and delicious!