Roast the bell pepper until the skin is black, using your favorite technique. (I do it under the broiler, checking and turning every 30 seconds or so.) When the pepper cools enough to handle, peel the skin and remove the seeds, seed membrane and stem. Chop coarsely.
Combine the egg yolks, mustard, 1 Tbs. of the lemon juice and the garlic in the bowl of a food processor (a blender also works--in fact, a little better). Run for about 45 seconds. Add the roasted pepper and run for another 10 seconds.
Combine the two oils. While the processor is running, add the oil in a slow, steady stream. Add the rest of the lemon juice, salt, and Tabasco. Refrigerate to thicken.
