Amounts are approximate, so use more or less of the aromatics if you like. And feel free to experiment. As long as you use the proper amount of liquid, you can't really go wrong. The squid should be almost, but not quite, submerged when the liquid is added. And if the stew begins to dry out during cooking, add a bit more crushed tomato or a few tablespoons of water.
2 tablespoons olive oil
1 tablespoon butter
1-2 shallots, chopped
1-2 cloves garlic, finely chopped
1 small carrot, finely chopped
1 small fresh chili pepper (optional)
1 tablespoon fresh parsley, chopped
1 1/4 pounds cleaned squid, bodies and tentacles, bodies sliced into 1/4-inch rings
1 1/2 cups canned crushed tomato
1/4 cup red wine
1 tablespoon tomato paste (optional)
In a pot large enough to hold squid and sauce, heat oil and butter on medium heat. Add shallot, garlic, carrot, chili (if using), and parsley, and cook for about 5 minutes until vegetables soften. If they begin to brown, lower heat (it's okay if the garlic becomes golden, but it shouldn't quite brown).
Add squid to pot, and stir to coat with aromatics. Cook over medium to medium-high heat for 1-2 minutes. Pour crushed tomato and wine over squid, and mix well. Bring to a boil over medium-high heat, stir in tomato paste (if using), and lower heat to low. Cover pot, but leave lid slightly ajar. Cook for about 40 minutes, stirring occasionally. Near end of cooking, check sauce and add salt if necessary.
Serve over cooked pasta (or grains), or in a bowl with sauce. Garnish with additional chopped parsley if you like.