Stashcook | Hearty Veggie Shepherd's Pie with Sweet Potatoes

Ingredients

• 3 large sweet potatoes, peeled and cubed
• 1 tablespoon olive oil
• 3 medium carrots, peeled and diced
• 1 large yellow onion, diced
• 3 cloves garlic, minced
• 1/2 pound cremini mushrooms, diced
• 1 3/4 cups green lentils, rinsed
• 850 ml vegetable broth
• 1 cup frozen corn
• 1 teaspoon dried rosemary
• 1 teaspoon dried thyme
• Salt to taste
• Black pepper to taste
• 2 tablespoons unsalted butter