IN A LARGE POT OR DEEP BRAISER, HEAT OLIVE OIL OVER MEDIUM HEAT. ADD CARROTS, ONION, AND CELERY. STIR AND SAUTE FOR ABOUT 5-6 MINUTES.
ADD THE GARLIC AND STIR UNTIL FRAGRANT. THEN ADD THE BALSAMIC VINEGAR, PAPRIKA, CUMIN, CAYENNE AND LENTILS, STIRRING CONSISTENTLY.
ADD THE VEGETABLE STOCK, SALT, AND PEPPER TO THE POT. STIR AND BRING THE STEW UP TO A SIMMER. COVER THE POT HALFWAY WITH A LID AND LET THE STEW SIMMER ABOUT 7-10 MINUTES. STIR IN THE LEMON JUICE.
SERVE THE STEW HOT WITH CHOPPED FRESH HERBS AND EXTRA LEMON.