Wash the Brussels sprouts under cold water, cut off the tough bottoms and remove any damaged outer leaves. Halve the Brussels sprouts lengthwise. Strip the fresh thyme leaves from the stems and chop them finely.
Heat a large frying pan over medium-high heat and add the olive oil or coconut oil if desired. Add the lean minced beef to the pan and cook for approximately five to seven minutes, stirring until crumbly and completely browned. Drain off any excess cooking fat if necessary. Add the halved Brussels sprouts and finely chopped thyme to the meat. Stir everything well and cook the mixture for eight to twelve minutes. Stir regularly to prevent burning and ensure even cooking.
Pierce a Brussels sprout with a fork to check if it is just tender. They should be soft enough to pierce but retain their firmness. Season the mixture to taste with Celtic sea salt and freshly ground black pepper and stir once more.
Divide the hot dish among the plates and serve immediately.