In a dutch oven or heavy stock pot, on medium heat, add the oil, onion, lentils and bell pepper. Saute for 2 to 3 minutes while stirring.
Add the chicken broth, pumpkin, ginger, curry and cumin, bring to a boil, then reduce to a simmer and cook covered for 25 minutes.
Add the salt, pepper and lemon juice
Taste and adjust seasonings as desired.