Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Entrant | Constructor | Chassis | Driver | Rounds |
| --- | --- | --- | --- | --- |
| Alfa Romeo SpA | Alfa Romeo | 158/50 | Juan Manuel Fangio | 1–2, 4–7 |
| Alfa Romeo SpA | Alfa Romeo | 158/50 | Giuseppe Farina | 1–2, 4–7 |
| Alfa Romeo SpA | Alfa Romeo | 158/50 | Luigi Fagioli | 1–2, 4–7 |
| Alfa Romeo SpA | Alfa Romeo | 158/50 | Reg Parnell | 1 |
| Alfa Romeo SpA | Alfa Romeo | 158/50 | Consalvo Sanesi | 7 |
| Alfa Romeo SpA | Alfa Romeo | 158/50 | Piero Taruffi | 7 |
| Scuderia Ambrosiana | Maserati | 4CLT/48 | David Murray | 1, 7 |
| Scuderia Ambrosiana | Maserati | 4CLT/48 | David Hampshire | 1, 6 |
| Scuderia Ambrosiana | Maserati | 4CLT/48 | Reg Parnell | 6 |
| T.A.S.O. Mathieson | ERA | E | Leslie Johnson | 1 |
| Peter Walker | ERA | E | Peter Walker | 1 |
| Peter Walker | ERA | E | Tony Rolt | 1 |
| Joe Fry | Maserati | 4CL | Joe Fry | 1 |
| Joe Fry | Maserati | 4CL | Brian Shawe-Taylor | 1 |
| Bob Gerard | ERA | B A | Bob Gerard | 1–2 |
| Automobiles Talbot-Darracq | Talbot-Lago | T26C | Yves Giraud-Cabantous | 1, 4–6 |
| Automobiles Talbot-Darracq | Talbot-Lago | T26C | Louis Rosier | 1, 4–6 |
| Automobiles Talbot-Darracq | Talbot-Lago | T26C | Philippe Étancelin | 1, 5 |
| Automobiles Talbot-Darracq | Talbot-Lago | T26C | Eugène Martin | 1, 4 |
| Automobiles Talbot-Darracq | Talbot-Lago | T26C | Pierre Levegh | 5–6 |
| Automobiles Talbot-Darracq | Talbot-Lago | T26C | Raymond Sommer | 6 |
| Ecurie Belge | Talbot-Lago | T26C | Johnny Claes | 1–2, 4–7 |
| Officine Alfieri Maserati | Maserati | 4CLT/48 | Louis Chiron | 1–2, 4, 6–7 |
| Officine Alfieri Maserati | Maserati | 4CLT/48 | Franco Rol | 2, 6–7 |
| Enrico Platé | Maserati | 4CLT/48 | Toulo de Graffenried | 1–2, 4, 7 |
| Enrico Platé | Maserati | 4CLT/48 | B. Bira | 1–2, 4, 7 |
| Joe Kelly | Alta | GP | Joe Kelly | 1 |
| Geoffrey Crossley | Alta | GP | Geoffrey Crossley | 1, 5 |
| Scuderia Achille Varzi | Maserati | 4CLT/48 4CL | José Froilán González | 2, 6 |
| Scuderia Achille Varzi | Maserati | 4CLT/48 4CL | Alfredo Pián | 2 |
| Scuderia Achille Varzi | Maserati | 4CLT/48 4CL | Nello Pagani | 4 |
| Scuderia Achille Varzi | Maserati | 4CLT/48 4CL | Toni Branca | 4 |
| Horschell Racing Corporation | Cooper - JAP | T12 | Harry Schell | 2 |
| Equipe Gordini | Simca-Gordini | 15 | Robert Manzon | 2, 6–7 |
| Equipe Gordini | Simca-Gordini | 15 | Maurice Trintignant | 2, 7 |
| Philippe Étancelin | Talbot-Lago | T26C | Philippe Étancelin | 2, 4, 6–7 |
| Philippe Étancelin | Talbot-Lago | T26C | Eugène Chaboud | 6 |
| Ecurie Rosier | Talbot-Lago | T26C | Louis Rosier | 2, 7 |
| Ecurie Rosier | Talbot-Lago | T26C | Henri Louveau | 7 |
| Cuth Harrison | ERA | B | Cuth Harrison | 1-2, 7 |
| Peter Whitehead | Ferrari | 125 | Peter Whitehead | 2, 6–7 |
| Scuderia Ferrari | Ferrari | 125 275 375 | Luigi Villoresi | 2, 4–5 |
| Scuderia Ferrari | Ferrari | 125 275 375 | Alberto Ascari | 2, 4–5, 7 |
| Scuderia Ferrari | Ferrari | 125 275 375 | Raymond Sommer | 2, 4 |
| Scuderia Ferrari | Ferrari | 125 275 375 | Dorino Serafini | 7 |
| Scuderia Ferrari | Ferrari | 125 | Peter Whitehead | 4 |
| Scuderia Milano | Maserati | 4CLT/50 | Felice Bonetto | 4 |
| Scuderia Milano | Milano-Speluzzi | 1 | Felice Bonetto | 7 |
| Scuderia Milano | Maserati - Milano | 4CLT/50 | Felice Bonetto | 6 |
| Scuderia Milano | Maserati - Milano | 4CLT/50 | Franco Comotti | 7 |
| Ecurie Bleue | Talbot-Lago | T26C | Harry Schell | 4 |
| Raymond Sommer | Talbot-Lago | T26C | Raymond Sommer | 5, 7 |
| Ecurie Lutetia | Talbot-Lago | T26C | Eugène Chaboud | 5 |
| Antonio Branca | Maserati | 4CL | Toni Branca | 5 |
| Charles Pozzi | Talbot-Lago | T26C | Charles Pozzi | 6 |
| Charles Pozzi | Talbot-Lago | T26C | Louis Rosier | 6 |
| Clemente Biondetti | Ferrari - Jaguar | 166S | Clemente Biondetti | 7 |
| Paul Pietsch | Maserati | 4CLT/48 | Paul Pietsch | 7 |
| Guy Mairesse | Talbot-Lago | T26C | Guy Mairesse | 7 |
| Pierre Levegh | Talbot-Lago | T26C | Pierre Levegh | 7 |
Question:
Who is the driver whose Constructor was Era, and whose entrant was T.A.S.O. Mathieson?
Answer:
Leslie Johnson