Cook the squash first. Heat a large pan over medium-high heat and when hot, add 1 tablespoon butter. When the butter melts, add the garlic and cook until fragrant, about 1 minute. Add the squash and cook, stirring frequently until just beginning to soften with a slight snap, about 5 minutes. Season to taste with salt and pepper and stir in half the basil. Transfer to a serving dish. In the now empty pan, add the tomatoes and cook until little to no liquid remains. Stir the tomatoes into the sautéed zucchini and top the whole thing with the remaining basil.

Without cleaning the pan, add 2 tablespoons butter or oil over high heat. When melted and hot, add the shrimp, season with salt and pepper to taste and cook until opaque and just cooked through, about 5 minutes. Remove the shrimp to a plate, retaining as much oil in the pan as you can.

Add the shallots and cook over medium-high heat until soft and translucent, about 5 minutes. Add the wine, if using and cook on high until little liquid remains, about 5 minutes. Add the stock, saffron, and heavy cream. Cook on high until reduced by half, about 5 minutes. Season to taste with salt and pepper and serve with the shrimp.