In a large skillet, heat butter until melted
Sautee onions until translucent
Add peppers and cook 2 minutes until softened
Add drained and rinsed can of lentil to the skillet. Cook until the exterior of the lentil shell is a little crispy, about 5-6 minutes
Add spinach and stir into lentils. Toss until spinach is wilted
Turn off heat
Add diced tomatoes and toss
Season with salt and pepper, if desired
Serve with a fried egg, optional