To make the pesto: Toast almonds and pistachios. Add everything to a food processor except the olive oil. Whizz, scraping down the sides as necessary, until well incorporated. With the motor running, slowly stream in olive oil until you reach your desired consistency (keep in mind that it will thicken a bit as it cools). Season well with salt and pepper, whizz again, and taste. Add more salt and/or lemon to taste. To make the salad: Toss the cut summer squash with olive oil and season with salt. Cook the pieces on a grill or in a hot pan (with more olive oil): place them with one cut side down, and don't touch for 30 seconds. You want to get a nice sear on one side while still leaving the squash al dente. Turn the pieces and cook for another 15 seconds, then remove from the heat and let cool. In a bowl, combine the tomatoes and their roasting oil, seared summer squash, sliced snap peas and ¾ cup of the mint leaves, and shower with a good bit of lemon zest. Toss gently and taste; add salt, black pepper, more roasting oil and more zest as desired. You want the vegetables to be draped in the luscious tomato roasting oil, with a tiny bit of it pooling at the bottom of the bowl. To serve, swoop the pesto across one side of a shallow serving bowl. Mound the tomato-summer squash-snap pea mixture in the center of the bowl. Shave ricotta salata over top (if you don't have a mandolin, use a vegetable peeler) until the tomato pile is nicely blanketed. Finish with the rest of the mint, more lemon zest, more freshly ground black pepper, and a shower of chive blossoms.