Clean and dice the meat.
Place in a heatproof dish. Season with salt, pepper, and 2 cloves of crushed garlic, then drizzle with olive oil. Mix thoroughly. Leave to marinate in the refrigerator for 1-2 hours.
Before baking, pour a little water over it and cover with aluminum foil. Place in an oven preheated to 200°C (392°F).
After 30 minutes, add the peeled and diced potatoes and celery, as well as the remaining garlic cloves, whole.
Continue baking for 15 minutes, then remove the foil and stir.
Bake for another 15 minutes without aluminum foil.