FOR THE SAUCE:

1. Preheat an oven to 400°.

2. In a roasting pan just large enough to hold them, place the pepper, the tomato halves, cut-side down and the unpeeled garlic cloves.

3. Roast until the pepper is tender and its skin slips off, and the tomatoes have released some of their juices and the skins slip off, about 35 minutes.

4. Remove, and when cool enough to handle, cut the pepper in half and remove the seeds and core.

5. Peel and discard the skin, then chop the pepper into three or four pieces.

6. Remove and discard the tomato skins.

7. Squeeze the garlic, releasing the roasted pulp and discard the skins.

8. Put the pepper, tomatoes, garlic, almonds, bread, salt and chile flakes in a blender and process until a thick paste forms.

9. Add enough of the olive oil to get a creamy consistency. Set aside until ready to serve.

FOR THE HALIBUT:

Put the cubed halibut in a non-reactive bowl and add the lemon zest, lemon juice, rosemary sprigs and minced rosemary, salt and pepper. Turn gently and marinate 20-30 minutes.

While the fish is marinating, soak skewers in water, 20-30 minutes.

1. Thread three to four pieces of halibut on each skewer.

2. Preheat a gas or charcoal grill to medium-high. Oil the grill rack and brush oil onto the halibut skewers.

3. Place the skewers about 6 inches away from the heat source, and grill, turning once, until golden on the outside and just opaque throughout, about 5 minutes per side.

Serve hot, accompanied by the romesco sauce.