Preheat the oven to 180 °C (160 °C fan). Chop the beetroot into small pieces and soften it with the onion in olive oil in an ovenproof frying pan until slightly tender.
Add the spinach and let it wilt briefly. Season everything with nutmeg and a small pinch of salt.
Whisk the eggs in a bowl and pour them evenly over the vegetables. Gently shake the pan so everything is well distributed.
Crumble the goat's cheese over the top and bake the frittata at 180 °C for 12–15 min, until the eggs have set and the top is lightly golden.
Leave the frittata to rest briefly so it's easier to slice.
Serve it warm, lukewarm or cold, straight from the pan or with a simple green salad.
Good to know
A frittata like this reliably rescues tiring days. Warm, savoury and still not too heavy.
Swaps
Goat's cheese → sheep's milk feta (similar protein content, often a stronger flavour); spinach → chard (also provides folate and fibre); olive oil → ghee (stable at high heat and full of flavour)
Allergens
Contains egg and milk. Usually suitable for children if the texture suits them; in pregnancy, only eat the frittata fully cooked and with pasteurised goat's cheese.