Add tomatoes and garlic to a baking sheet. Drizzle with 2 tablespoons olive oil and toss. Cook in the oven for 15 minutes.
While tomatoes are cooking, cut the bread into 2 equal pieces, then slice each in half to form 4 open-faced slices. Put the extra 1 tablespoon olive oil in a small bowl, and with a pastry brush, brush the olive oil all over the open faces.
Tear or slice the basil leaves into small pieces.
Once the tomatoes have been cooking for 15 minutes, add the bread to the sheet pan and return to the oven for an extra 5 minutes. After 5 minutes, remove from the oven (or broil for an extra 1-2 minutes if needed).
Take the roasted garlic cloves and squeeze out of their paper skins. Spread onto toasted bread slices. Place onto plates and top with roasted tomatoes and basil leaves. Sprinkle with salt and pepper to taste.
Notes
A few tips on making the recipe:
Leave the garlic in the wrapper/skin. If you take it out of the wrapper, it has a higher chance of burning and getting bitter. You can also wrap the garlic cloves (still in the skin) in foil to help ward against the potential for it burning. If your garlic is looking pretty brown, remove it from the sheet and set aside before adding the bread and baking for an additional 5 minutes.
When you're spreading oil on the bread, make sure to get all the way to the edges! If you have missed the edges and you broil it, the edges wind up burning.