Heat a large heavy-bottomed skillet over high heat and add 1 tablespoon of the olive oil.
Add the sliced bell peppers and sauté just until a few of the edges are blackened and the peppers have softened just slightly. Remove to a plate.
Reduce the heat to medium and add the other tablespoon of olive oil.
Add the onions and garlic and sauté just until soft and translucent.
Add the lentils, mushrooms, taco seasoning, and paprika and stir over the heat until the mushrooms begin to release some juices and the mixture becomes fragrant.
Add the water 1/4 cup at a time just to create a thick sauce - you may not need to add the whole 3/4 cup.
Let the mixture reduce over low heat for about 15 minutes, stirring regularly, until the mushrooms are very soft.
Add the bell peppers and stir to combine.
Serve immediately in soft tacos, lettuce wraps, or over a salad, or chill and re-heat for breakfast, lunch or dinner another day!