4 medium-sized yellow or green summer squash, or a mixture of colors, sliced lengthwise and then into 1/4 inch slices (about 8 cups sliced squash)
1 T olive oil (or less, depending on the pan)
1 T minced garlic
2 T fresh thyme leaves or 1 T dried thyme (or less if you're not that fond of thyme)
2 large eggs
1/3 cup light sour cream
1 cup crumbled feta (not tightly packed)
2 T grated parmesan cheese
1 T lemon juice
salt and fresh ground black pepper to taste
Preheat oven to 375F/190C. Wash and dry squash, then cut off stem and blossom end and discard. Cut squash lengthwise in half, then slice into half-moon slices about 1/4 inch thick. (I used a mandoline with the 7mm blade, but you can use a knife.)
Heat olive oil in large non-stick frying pan, add garlic and thyme leaves and saute about 45 seconds (just long enough to season the oil, don't let the garlic brown.) Add squash slices and saute about 4 minutes, turning a few times. Squash should be barely starting to soften.
While squash cooks, break eggs into a small bowl or glass measuring cup and beat until egg yolks and whites are combined. Stir in sour cream, feta, parmesan, and lemon juice.
Spray a 2 quart gratin dish or glass casserole dish with non-stick spray or olive oil. Layer half the squash in the dish, then season with salt and fresh ground black pepper. (Remember the feta is salty, so it won't need a lot of salt.) Pour over half the egg-feta mixture and use the back of a spoon or a rubber scraper to spread it over the squash. Repeat with another layer of squash and the rest of the feta-egg mixture.
Bake at 375F/190C for 40-45 minutes, or until the mixture is bubbling, slightly set, and top if lightly browned. Serve hot.
This will keep in the fridge for a day or two. For best results, I recommend reheating in a toaster oven. Do not freeze.
