Heat oven to 200C/180C fan/gas 6. Put the mushrooms and tomatoes into 4 ovenproof dishes. Divide garlic between the dishes, drizzle over the oil and some seasoning, then bake for 10 mins.
Meanwhile, put the spinach into a large colander, then pour over a kettle of boiling water to wilt it. Squeeze out any excess water, then add the spinach to the dishes. Add the bacon and make a little gap between the vegetables and crack an egg into each dish. Return to the oven and cook for a further 8-10 mins or until the egg is cooked to your liking.