Preheat the oven to 450

Drizzle evo on the baking sheet and add the tomatoes flesh side up. Sprinkle the tops of all the tomatoes with course kosher salt, Italian seasoning, fennel and drizzle olive oil over the tomatoes, roast 450 for 20 minutes. Turn up the heat to 500 and roast for an additional 15 minutes.

Add 4 tbsp of butter to a large skillet and add the onion, a couple healthy pinches of course kosher salt and sauté the onions stirring frequently until they start to brown and caramelize. When they are pretty caramelized add the garlic until it starts to brown and remove from the heat.

Add the tomatoes and all juices to a food processor followed by the basil and caramelized mixture. Pulse until the basil has broken down but the mixture is not too smooth. Add two tbsp of butter until melted and taste for salt.