Preheat the oven to 350 Deg C. Place the roast into an ovenproof dish or roasting pan.
Pour a little oil into a saucepan and fry the onions until golden brown.
Add the rest of the ingredients, bring to the boil, stirring continuously, then reduce the heat and allow it to simmer for a few minutes.
Pour over the meat and roast in the oven, uncovered, for 30 minutes. Turn the roast over and roast it, again uncovered, for a further 30 minutes.
Reduce the heat to 320 Deg. F and let it enjoy its long, hot relaxation period, covered, in the oven for about 1 1/2 - 2 hours.
Remove the lid and baste the roast. It should have a nice rich, dark glaze to it. If you find it hasn't, turn up the heat a little to about 400 deg F and cook it a little longer until it gets that thick, glazed, saucy look!
Tips: Tomato Jami can be made by mixing 1 tablespoon apricot jam with 2 tablespoons tomato paste.
to make your own peri-peri oil: Blend 4 ounces red hot chili peppers, 6 cloves garlic, 1 tablespoon sugar, 1 tablespoon lemon juice, and 1 cup oil. Keep refrigerated until ready for use.