Preheat the oven to 220 degrees
Peel the sweet potato and cut it into cubes
Chop the onion
Place the cubes of sweet potato on the tray
Add 1 tbsp of olive oil, thyme, salt and pepper and mix it by hand
Place on the middle tray and let it bake for 10 minutes
Halfway through add the onion to the tray and let it bake for 5 minutes
Cut the tomato into cubes
Slice the goat cheese and cut it into small pieces
Take it out of the oven and let it cool down
In a salad bowl, place the cooked lentils, add the tomatoes, the sweet potatoes and the onion
Pour the sauce and mix it well until absorbed
Sprinkle with goat cheese on top
Add salt and pepper for taste