Preheat oven to 200°C and line a baking sheet with parchment paper.
Dice the yellow potatoes into 1cm cubes and toss with half of the olive oil, sea salt, and black pepper.
Spread the potatoes in a single layer on the baking sheet and roast for 20 to 25 minutes until golden and crispy.
While potatoes roast, finely dice the onion, carrot, and celery, and mince the garlic.
In a non-stick skillet over medium-high heat, brown the ground beef until cooked through, then drain any excess liquid.
Add the remaining olive oil to the skillet along with the onion, carrot, celery, and garlic, sautéing until the vegetables are tender.
Stir in the tomato puree and dried oregano, then reduce the heat to low and simmer for 10 minutes to allow the flavors to meld.
In a small bowl, toss the mixed baby greens with the balsamic vinegar.
Serve the beef bolognese over the roasted potatoes with the side salad on the plate.