Put a large pot of salted water on to boil.

Heat the olive oil in the largest skillet or wide, heavy-bottomed pot you have over medium-high heat. Add the garlic and fennel slices and season with salt and pepper. Cook, stirring occasionally, until the garlic and fennel are lightly browned and completely tender, 8 to 10 minutes.

Add the fennel seeds and crushed red pepper flakes, stirring to toast a bit. Add the tomatoes and season with salt and pepper. Cook until the tomatoes nearly all burst and are broken down into a jammy, sauce-y sauce, 10 to 12 minutes (using a wooden spoon or spatula to kind of gently crush them as they cook is a good idea).

eanwhile, the pasta water should be boiling at this point, so go ahead and drop the pasta into the pot, cooking it to a nice al dente (timing will vary depending on pasta, so best to follow instructions on the package). Drain the pasta, reserving about ½ cup pasta water.

Add the wine and continue to cook until the sauce is reduced by about half, 4 to 5 minutes. Add the shrimp, season with salt and pepper, and toss to coat, continuing to cook until all the shrimp are opaque and cooked through, another 3 to 5 minutes.

Since the skillet or pot is likely getting a little crowded, I like to toss my pasta with all of the tomato-y seafood business in the largest bowl I have, adding a bit of pasta water as I toss to keep things saucy. Season with salt, pepper, and more crushed red pepper flakes, if you like.

Transfer the mixture to a large serving bowl.