Raina's Vegan Lentil Sloppy Joes

Heat oil in a skillet over medium heat; add onion and saute for 2 minutes. Add celery; cook and stir for 2 minutes. Add garlic and cook until fragrant, about 2 minutes. Stir in thyme, oregano, parsley, chili powder, paprika, and pepper until vegetables are evenly coated.

Stir in lentils until evenly coated. Add water, tomatoes, and tomato paste; mix well. Stir in yellow and brown mustards, Worcestershire sauce, chile paste, and maple syrup. Cover and simmer over low heat until lentils are tender, 35 to 45 minutes.

Serve each sandwich open faced on a slice of bread topped with avocado.