Spring Picnic Frittata

olive oil

onion, diced

cooked potatoes (slices, homefries, hash browns...)

shredded cheese (comté, parmesan, sharp cheddar...)

cooked, smoked protein (ham, bacon, duck, tofu...)

green spring veggies, cooked (and drained if needed) (broccoli, peas, green beans, spinach...)

eggs

salt and pepper