4 tablespoons olive oil, divided
1 medium onion, chopped
1 medium carrot, finely chopped
2 large garlic cloves, chopped, divided
2 tablespoons curry powder, or more to taste
1 cup French green lentils
4 cups water
1 15-ounce can chickpeas, drained, rinsed
1 tablespoon fresh lemon juice
2 tablespoons butter
2 green onions, thinly sliced
1 lemon, cut into wedges