In a large bowl, combine the ground turkey, grated asiago cheese, pressed garlic, and breadcrumbs. In a small bowl, beat the egg with the salt and pepper until combined, then pour it over the turkey mixture. Mix gently with your hands or a fork until just combined — do not overmix or the meatballs will be dense. Using a teaspoon measure or small cookie scoop, roll the mixture into small meatballs about 1 inch (2.5cm) in diameter.

Heat the olive oil in a large heavy-bottomed pot or Dutch oven over medium heat until the oil shimmers. Working in batches of 8–10 meatballs, add them to the pot and cook for 2 to 4 minutes, turning gently with a wooden spoon, until evenly browned on all sides. Transfer each batch to a plate. Do not overcrowd the pot — leaving space between the meatballs ensures they sear rather than steam.

Once all meatballs are browned and set aside, pour half the chicken stock into the pot and use a wooden spoon to scrape up all the browned bits from the bottom — this fond is where most of the soup's depth of flavour comes from. Add the remaining stock, water, and canned diced tomatoes. Stir and bring to a gentle boil.

Once the soup reaches a gentle boil, reduce the heat to medium-low, add the elbow macaroni, and simmer for 2 to 3 minutes. Return the browned meatballs to the pot and simmer for 10 to 12 minutes, stirring occasionally. The meatballs should float to the surface and reach an internal temperature of 165°F / 74°C — check a few with an instant-read thermometer. The pasta should be al dente.

Remove the pot from direct heat or reduce to the lowest setting. Stir in the baby spinach and let it wilt for 1 to 2 minutes — the residual heat is enough. Season with salt and pepper to taste. Ladle into bowls and top each serving with freshly grated asiago cheese.