Prepare a 9″x13″ glass casserole dish with non-stick spray.
Thinly slice squash and onions then place in casserole dish. Coat veggies lightly with extra virgin olive oil, salt & pepper. Add green chiles and pepper jack cheese. Stir until mixed.
In a separate bowl, lightly whisk eggs and milk. Pour over the veggies evenly. Gently press squash down with fork.
Sprinkle the crushed bread crumbs over the squash mixture. Cover with aluminum foil and bake in a 350 degree oven for 1 hour. Uncover and continue baking for an additional 15 minutes until the top is browned.