Spray a pan with olive oil spray and bake mushroom caps at 350 for 15 mins while you prepare other ingredients.
Cook lentils and chia seeds according to lentil directions but with 75% more water (gotta account for chia seeds). Dice the vegetables.
In a frying pan sprayed with olive oil spray, cook diced vegetables until there’s only a slight crunch, then add the tomatoes and let simmer. Stir in chia seeds & lentils (drain water if any wasn’t absorbed).
Remove mushrooms and stuff the caps as high as you can with filling. Top with daiya and bake an additional 15 mins.