Drizzle a generous amount of extra-virgin olive oil (about ¼ cup) in the bottom of a 9 by 13-inch baking dish (or equivalent.)
Add mini San Marzano tomatoes or cherry tomatoes and very thinly sliced or chopped garlic to the dish and toss so that the tomatoes and garlic are well coated in oil.
Place a 7 oz. block of feta cheese in the middle of the tomatoes in the dish, sprinkle the top of it with dried chili flakes, a few grinds of black pepper, and drizzle it with a little more olive oil.
Bake the feta, tomatoes and garlic at 400°F. for 30 minutes or until the tomatoes have burst and the cheese has melted and is creamy. It should be soft enough so that you can easily spread it with the back of a spoon.
Meanwhile, as the feta is baking, slice and sauté a cup of mushrooms in a small amount of oil in a skillet.
Remove the dish from the oven and add a handful of chopped basil leaves and a couple of handfuls of baby spinach leaves. Stir to combine the melted feta cheese with the tomatoes, their juice and the greens. Add the sautéed mushrooms.
Boil 8 oz. of gluten-free pasta in salted water until it has almost reached the al dente stage. Remove half a cup of the pasta water and set aside, then drain the pasta.
Add the cooked pasta to the feta cheese dish and stir to combine. You may need to add a little of the pasta water to help the sauce thicken.
Garnish with more fresh basil and/ or dried oregano, a few grinds of freshly cracked pepper, and serve while hot.
A block of feta cheese will work much better than the crumbled feta as it has more moisture and will result in a creamier texture.I found whole cloves of garlic did not soften enough in the 30 minutes it took to roast the tomatoes and melt the feta. Slice them thinly, or chop or mince the cloves before adding to the tomatoes so they'll be soft enough to stir into the sauce. 7 ounces of feta cheese is just the right amount. I've made this recipe before using more cheese, and it was just too much.It's best to slightly undercook the pasta as it will continue to cook in the warm feta-tomato sauce. Cook it to a point just before the al dente stage. Some brands of gluten-free pasta tend to fall apart when overcooked, so keep this in mind.Save half a cup or so of the pasta water to pull the sauce together as you add the pasta. The starch in the pasta water not only adds flavour but it helps to thicken the sauce.