Fashion small rectangular molds from aluminum foil.
Brush the molds with olive oil. Cut tomatoes and feta cheese into slices and layer them alternately in the molds, scattering parsley between the layers.
Mince the garlic and scatter over the tomatoes and feta. Drizzle with olive oil and season with salt and pepper to taste.
Place the molds on a grill preheated to medium-high heat and grill for 10-15 minutes until the cheese melts and the tomatoes soften.