Heat 1 tablespoon olive oil in a dutch oven over medium. Add the onion and cook for 2 minutes, or until translucent. Add garlic and cook for another 30 seconds.
Increase the heat to medium-high and add the chicken to the pot. Stir occasionally until browned on all sides, about 3 minutes.
In a measuring cup with a spout, whisk together the vinegar, sugar, and chicken broth. (This is your non-alcoholic substitute for sherry wine.)
Stir in the broth, tomatoes, sherry wine substitute, chicken base, curry and salt. Bring to a boil, then reduce the heat to medium. Stir in the lentils. Cover and simmer for 20 minutes, or until the lentils are al dente, stirring occasionally. If the lentils are still crunchy, add another 5 minutes to the cooking time. (Be careful not to overcook the lentils or they will turn mushy.)
Stir the brown sugar into the cream until it is dissolved, then stir into the stew until heated through.
Remove the pot from the heat. Whisk the essential oils into the remaining ½ tablespoon olive oil and pour the oil mixture into the stew. Stir well to make sure the essential oil flavors are evenly distributed for the best seasoning.