Shepherd's pie with blue potatoes

Ingredients:

• 1 tbsp. l. olive oil
• 1 large white onion
• 2 stalks of celery
• 1 large carrot
• 2 cloves of garlic
• 900 g organic ground beef (16% fat)
• 1 tbsp tomato paste
• 180 ml of red wine
• 1 cup beef broth
• 3 sprigs thyme, leaves only
• 2 bay leaves
• Ground black pepper
• 900 g of purple potatoes
• 4 tablespoons unsalted butter at room temperature
• 0.5 cups of milk
• 5 cups of mixed cherry tomatoes
• 4 cups baby spinach
• 4 cups grated orange cheddar

Preparation:

1. Preheat oven to 190°C.
2. Heat oil in a large, heavy-bottomed skillet over medium heat. Finely chop the onion, add it to the skillet, and season with salt. Repeat with the celery and carrots and sauté the vegetables and onion until softened, 8–10 minutes, stirring frequently to prevent the onion from burning.
3. Once the vegetables have softened slightly and the onion is translucent, grate the garlic into the pan. Stir for a minute until fragrant, then add the ground beef. Use a wooden spoon to break up the ground beef and continue stirring until all the meat is browned, about 10 minutes. At this point, add the tomato paste, then the red wine, stirring to combine.
4. Pour in the beef broth and bring to a boil. Reduce the heat, add the thyme, bay leaf, and a good pinch of salt and black pepper. Cook for 15–20 minutes, until a thick meat sauce forms. Remove from heat.
5. Peel and dice the potatoes. Add to a large pot of salted boiling water and cook until tender when pierced with a fork, about 25 minutes. Drain completely. Mash the potatoes with a potato masher, leaving some chunks for texture. Add the butter and milk, and season with salt and pepper to taste.
6. Now all the ingredients for the rainbow pie are ready. Spread a thick layer of meat sauce into a 22x32 cm glass baking dish.
7. Halve the cherry tomatoes crosswise and arrange them cut-side down on top of the beef, making sure there are no gaps. Cover the tomatoes completely with spinach, pressing lightly and tucking in the corners. Sprinkle the spinach with cheese (it will be chewy in the oven). Spoon the mashed potatoes on top and smooth them out so that the entire surface is covered and the spinach is hidden. Use the back of a spoon to create a textured surface so the edges will brown in the oven.
8. Bake until crisp and bubbly, and the tomatoes are juicy, 30–35 minutes. Let the pie rest for 10 minutes and serve.