Place the venison cubes into a large resealable bag. Add the red wine, 2 tablespoons of olive oil, seasoned salt, allspice berries and pickled garlic. Seal the bag and turn to distribute the ingredients. Refrigerate overnight to marinate.
Preheat the oven to 165 degrees C.
Heat 1 tablespoon of olive oil in a casserole dish over medium-high heat. Add the red onions; cook and stir for a few minutes. Add the venison and continue cooking until it is browned. Add the marinade from the bag and allow to simmer over low heat while you prepare the lentils.
Rinse the lentils and place in a saucepan. Fill with enough water to cover the lentils by at least 3cm. Cook until almost tender, about 20 minutes. Drain and transfer the lentils to the casserole dish. Add the pearl onions and carrot chunks and cover with a lid.
Bake in the preheated oven until the venison is very tender, about 1 hour.