Japanese Curry With Winter Squash and Mushrooms

Name: Japanese Curry With Winter Squash and Mushrooms
Ingredients: 4 Tbsp. unsalted butter; ¼ cup all-purpose flour; ¼ cup S&B curry powder; 2 tsp. garam masala; 3 Tbsp. vegetable oil, divided; 8 oz. mixed mushrooms (such as maitake, royal trumpet, shiitake, and/or crimini), torn or sliced into 2 pieces; Kosher salt, freshly ground pepper; 1 large onion, chopped; 1 medium carrot, peeled, sliced on a diagonal ½ thick; 2 celery stalks, sliced on a diagonal ½ thick; 3 garlic cloves, finely chopped; 1 1 piece ginger, peeled, finely chopped; 6 cups low-sodium vegetable broth; 12 oz. kabocha squash, scrubbed, or other winter squash, peeled, seeds removed, cut into 1 pieces (about 2½ cups); 1 Tbsp. plus 1 tsp. honey; Thinly sliced scallions and cooked short-grain rice (for serving)