Mushroom Rice Pilaf (a one-pot meal)

Ingredients

• 1 large or 2 medium onions, about 2 1/2 cups, finely chopped
• 1 lb white button mushrooms, sliced
• 2 Tbsp olive oil
• 4 Tbsp unsalted butter, divided
• 2 garlic cloves, minced or pressed
• 1/2 cup white wine
• 2 cups long grain rice, such as basmati
• 4 cups low sodium chicken broth
• 1 tsp salt, or to taste
• Pinch of black pepper
• 2 Tbsp Fresh dill for garnish, optional