Slice the onion while the other vegetables rest in salt. In a large pan, melt butter and add olive oil over medium-medium low heat. Sautee garlic and anchovy paste briefly, until fragrant. Toss in the onions and cook until slightly softened and yellow. Working in layers, add squash and zucchini, lightly salting and adding fresh ground black pepper to each layer. Add cooked okra. Scrape up good brown bits by deglazing with a decent splash of beer or white wine, if you happen to be drinking it at the time. Or crack some open. Pour in half the porchini broth, reducing, and continue to add the rest of the liquid, slowly simmering down to a slight pool. The luscious vegetables should have all but fallen apart, relenting to the porcini broth. Swirl in the spicy sriracha and adjust seasonings. Do enjoy!