Pre-heat your oven to 350°F
Place the spinach in a strainer and let the excess water drain, (press to get most of the water out).
Place the spinach on a cutting board and give it a coarse chop.
Saute the mushrooms in a skillet on medium heat with 1 tbsp olive oil, until all the water has evaporated, 6 or 8 minutes, remove and place in a bowl.
Saute the pepper and zucchini, adding another tbsp olive oil if necessary, until soft, 5 minutes. Remove and cool in a bowl.
Mix the remaining ingredients in a large bowl, (with 3 tbsp olive oil), stir to combine.
Add the mushrooms, peppers and zucchini and fold in.
Oil a 9 1/2 inch pie plate and add the ingredients.
Bake in a 350° oven for 45 to 55 minutes until the edges start to brown.
Let the quiche cool for 15 minutes before cutting, then serve.